DE19549357A1 - Process for reducing the lost energy in communication systems and communication systems - Google Patents

Description

The invention relates to a method for reducing the lost energy in communication systems where one first station with a first plurality of second stations is used, as well as corresponding communication systems.  

Background of the revelation

Passed on conventional satellite communication systems Responders earlier from a number of separate power ver stronger, each carrying multiple signals. The working point each amplifier was normally set to a average output level was generated, which is significantly below was half the saturation output level of the amplifier maintain linear operation.

However, U.S. Patent No. 3,917,998 to Welti describes with the Title "Butler Matrix Responder" an arrangement of N gekop pelten power amplifiers for amplifying N signal paths. The N signal paths considered include the transmission of Signals from at least one ground station to N locations on the Earth using an orbiting satellite. The before part of using coupled amplifiers versus ver using a number N of non-coupled amplifiers is that the set of uncoupled amplifiers on generating is limited to a performance that exceeds the peak performance against a single amplifier in any signal path does not exceed, whereas the technology, the coupled Amplifier used that allows generation of power which is equal to the sum of the powers of all of the amplifiers in is any signal path, provided that all signal paths no more than the average power at the same time require. As a result, signals are above and vary below an average power level, in adjusted more efficiently due to better stati tical averaging of the power from the N signal paths is requested. The matrix power amplifier of the Welti patent is for use in frequency division multiples access (FDMA) applications and gives the opportunity to Number of FDMA carrier frequencies in each signal path are used, and accordingly the performance, which in Every signal path is needed over a wide range  vary.

A matrix power amplifier according to the Welti patent contains a Butler matrix for combining a number N of On signals to be amplified by N different to generate combinations of the input signals. Additional Lich a set of N power amplifiers is provided, so that each amplifier amplifies one of the combinations to N to generate amplified signals. The matrix power amplifiers also contain a Butler matrix to combine the ver strengthened signals to produce N outputs that amplified Are versions of the original N input signals. Of the Advantage compared to simply reinforcing the ur initial N inputs in independent amplifiers is that Fortune, when suddenly needed, more than that Power of a single amplifier for one of the N signals determine paths. Basically, the matrix performance amplify the sum of the power outputs of all amplifiers provide a single output.

The properties of cross modulation, generated by non-linearities in a matrix power amplifier, are different from those in a single amplifier. It can be shown that third order cross modulation between signals input to inputs 1 and J of the input butler matrix, respectively, occurs on output numbers ( 2 i-j) _N and ( 2 j-i) _{N of} the output butler matrix . As a first step in reducing cross-modulation in a matrix power amplifier, one embodiment of the present invention provides an excess number of gain paths so that outputs ( 2 i-j) or ( 2 ji) or their corresponding inputs are not used as desired signal outputs , but end in irrelevant loads. Thus, third order modulation between signals i and j will not be transmitted. This requires that the number of Butler Matrix input and output ports M be greater than the number of signals N to be amplified, with the remaining MN signals ending in insignificant loads.

It is easy to see that if only two signals are to be amplified, using ports 1 and 2 as inputs and outputs will result in third order cross modulation occurring on ports 0 and 3 , which are closed. It is not so obvious how this is achieved when there are many signals. However, Babcock has solved this problem in a different context. Babcock wanted to find a method of assigning frequency channels on an equally divided grid, for signals amplified by the same nonlinear amplifiers, such that third order cross modulation between any two or three signals would not fall into a channel from a signal is used. The mathematical formulation of the problem is the same as for the matrix power amplifier of the invention, with a set of integers I1, I2, I3. . . is found such that Ii + Ik-Ij is not in the set. The solution is called "Babcock spacing". Babcock uses these integers to choose from M frequency channels for the transmission of signals. However, the present invention uses Babcock's integer sets to choose from M spatial output channels that are selected for N desired signals. Thus, the first improvement over the prior art matrix power amplifier of the present invention is to use a larger matrix than the number of signals to be amplified and to assign inputs and outputs to signals or not, according to Babcock spacing or other optimal assignment , so that it is ensured that cross modulation basically exits from outputs to which signals are not assigned.

There is also on the current cellular communication  market an emphasis on making mobile phones small, to manufacture portable units that are used with, again rechargeable batteries work. A parameter of great Time is of interest to users of such phones duration that can be spent in entertainment without that you have to change or recharge the battery. This Parameter is simply known as the "talk time" by different types of mobile phones is offered. Of course it is possible to offer a longer talk time, by using larger batteries, but increase the larger batteries the size and weight of the mobile Phone. Therefore designers and inventors strive, Vorrich to design that for a given battery capacity reach longer office hours. During a conversation tion, the radio transmitter power amplifier is the predominant one Power consumer. The efficiency of the amplifier at the Conversion of battery energy into radio energy therefore has one direct influence on the length of the available speaking time for a cellular mobile phone.

Cellular telephone systems were first introduced by Analog frequency modulation was used to add a voice to impress a radio signal. Analog frequency modulation has that Advantage that a constant amplitude signal is generated, whose phase angle changes. The most powerful Transformer power amplifiers can be used for constant amplitudes signals are built in a saturated output mode work.

Original cellular systems using analog frequency modulation were also duplexers, which means that they received a signal in the opposite direction at the same time that they were transmitting a signal. A device known as a duplexer has therefore been needed to couple both the transmitter and the receiver with the same antenna, so that interference is avoided. As shown in FIG. 1 (a), the antenna 12 is connected to the duplexer 16 , which is composed of the filters 11 and 13 . The duplexer 16 then controls signals to and from the power amplifier 10 and the receiver 14 so as to avoid interference. Figure 1 (b) illustrates the addition of an isolator 15 in the transmit path, which in some cases is used to protect the transmitter against antenna mismatches and / or to protect the transmitter from other signals picked up by and in the antenna Transmitters are fed back, causing an undesirable phenomenon known as reverse cross modulation. The isolator 15 deflects signals reflected from the antenna mismatch or obtained from other sources into an insignificant load 18 . The prior art does not disclose the recovery of energy dissipated into the trivial load to increase the talk time of portable radios. A transmitter power amplifier as illustrated in FIG. 1 (a) may be a single power amplifier.

A transmitter power amplifier can also be constructed by combining two similar, smaller size amplifiers. When the amplifier devices are operated in antiphase and their outputs are combined with a relative phase of 180 degrees so that their outputs add up constructively, the amplifier is known as a push-pull amplifier. Sometimes two similar amplifiers 20 and 21 can be operated 90 degrees out of phase and their outputs are combined using a 90 degree or quadrature coupler as illustrated in FIG. 2. The quadrature coupler 23 can be formed by operating two stripe transmission lines in parallel close to each other. The energy is transferred between these lines in such a way that a signal flowing from left to right on one line induces a signal flowing from right to left on the other line, but with a phase shift of 90 degrees. Thus, two amplifiers, each connected to the left end of a first line and the right end of a second line, will generate signals running left to right on the first line and right to left on the second line.

When the amplifiers are operated approximately 90 degrees out of phase, the eventual signal flowing on the first line becomes a sum signal and the eventual signal flowing on the second line is a difference signal that can be designed such that it is zero. The output of the differential line usually ends in an insignificant load 24 , which normally does not require any power. However, practical tolerances of matching between the amplifiers, the accuracy of the phase shift, energy at harmonic frequencies or antenna mismatch at the output of the sum line can lead to significant energy consumption in this trivial load. The prior art does not disclose the recovery of this otherwise lost energy in order to extend the talk time of a portable radio.

Yet another configuration of a power amplifier, known as a feed-forward amplifier, can be used in some circumstances where linear power amplification is desired instead of saturated power amplifiers from class C amplifiers. In controlled power amplifier configurations, a more or less nonlinear amplifier 30 produces an output signal which is then corrected by adding an error signal generated by an error amplifier 31 to the output signal, with a directional coupler 32 as described above and as it is As shown in Fig. 3, is used. A signal of lost energy that is normally generated in the trivial load 33 corresponds to the undesired difference signal. The unwanted difference signal is always generated when two dissimilar signals with overlapping spectra are added to each other. Again, the prior art does not disclose recovering the lost energy generated by the difference signal to extend the talk time.

Summary of the revelation

It is an object of the present invention to address the shortcomings of the To overcome the state of the art and an effective Einrich device for amplifying multiple signals on a transmission line to provide power level, whereby power ampl ker used to efficiently amplify Constant amplitude signals are designed, like class C amplifier, with high levels of cross modulation products be avoided.

An embodiment of the present invention is disclosed an amplifier device for linearly amplifying a desired signal, with a pair of coupled, non-linear Amplifier is used. The amplifier device has Limiting devices for separating amplitude variations from the desired signal and to generate a constant amplitude signal, which is the phase of the desired signal carries, and one related to the amplitude Signal on. In addition, a driver signal generator generates set up two driver signals, each depending on the Constant amplitude signal and from that to the amplitude in Related signal so that each driver signal from depends on the phase of the desired signal and such that the Sum of the squares of the amplitudes of the driver signals constant is. Finally, a coupling device couples the two Driver signals to drive two constant amplitude signals of the pair of nonlinear power amplifiers and for coupling of the outputs of the power amplifiers to produce two to generate amplified power signals, one of them the linearly amplified desired signal and the other of  is a signal of lost energy.

Another embodiment of the present invention relates to a communication system which is a first station used with a first plurality of second stations using a phased array antenna. The System has a signal generating device for generating a first plurality of signals for transmission respective second stations, with radio wave modulation is used. Combination devices then produce one Large number of combined signals, the complex weighted sums of the first plurality of signals, the second Variety corresponds to the number of antenna array elements that arranged along a first dimension of the phase arrangement are. In addition, driver signal generating devices generate a third of each of the second plurality of signals Variety of signals, the number of different groups of elements that correspond along a second dimension the phase arrangement are arranged. Reinforcement devices are provided to the second plurality of signals amplify, the third plurality of signals each Transmit power amplifiers are used which are designed that they send constant amplitude signals. After all, one is Antenna device connected to the amplifier device, so that desired signals are radiated in desired directions and unwanted signals are scattered in other directions will.

In another embodiment of the present invention The present invention relates to methods of answering back a variety of TDMA signals from one satellite in one Satellite communication system and in particular an arrangement of the satellite power amplifiers, so something flexible to raise the power level in certain TDMA time slots to offer.  

It is another object of the present invention that overcome the above problems by the lost Energy is recovered by the power amplifier is generated to the available amount of talk time for one to increase portable, mobile phone. An embodiment The present invention relates to a device for Increasing the energy efficiency of an amplifier, wherein Feed-forward (controlled) linearization is used. The Device has a DC power source that Power to the amplifier that gives a main output signal generated. A second amplifier amplifies an error signal. A combining network then combines the error signal with the main signal to a corrected sum signal and a Generate signal for lost energy. Finally walks a rectifier converts the lost energy signal into one DC current that is fed back to the DC power source pelt to reduce the final energy consumption gladly.

Detailed description of the drawings

These and other features and advantages of the invention will be easily clear to a person skilled in the art from the following description, used together with the drawings in which:

Fig. 1 (a) - (b) a conventional power amplifier of coupling illustrate to an antenna;

Figure 2 illustrates a conventional quadrature coupled amplifier;

Fig. 3 illustrates a conventional controlled Linearisierungsver stronger, attached to an antenna;

Fig. 4 is an over-dimensioned matrix power amplifier veran illustrates an embodiment of the present invention shown in;

. Light 5 is a linear power amplifier of the class C in accordance with an embodiment of the present invention is shown;

6 is a N-channel matrix power amplifier light Fig illustrated, the two N used class C amplifier, according to an embodiment of the present invention.

Fig. 7 illustrates a general matrix power amplifier of the class C in accordance with an embodiment of the present OF INVENTION dung;

Fig. 8 is a signal generator for generating phase-modulated drive signals illustrating an embodiment of the present invention shown in;

Figure 9 illustrates a cylindrical array of slot antennas and a phase or base station;

FIG. 10 is a transmit matrix processor according to one embodiment of the present invention is illustrated;

FIG. 11 is a block diagram of a heat reduction method illustrates an embodiment of the present invention shown in;

FIG. 12 is a block diagram of the recovery of power reflected illustrates an embodiment of the present OF INVENTION dung invention;

Fig. 13 illustrates a graphical representation showing effective transmit efficiency against antenna mismatch, with and without an embodiment of the present invention;

Figure 14 graphically illustrates the increase in talk time using an embodiment of the present invention to recover lost energy;

FIG. 15 is the recovery of waste energy in hybrid coupled amplifiers illustrates an embodiment of the present invention shown in;

Fig. 16 according illustrates a controlled amplifier having an improved efficiency of an embodiment of the present invention;

FIG. 17 is a graphical representation of the multi-carrier Sendewir illustrates an embodiment of the present invention according to kung grads;

FIG. 18 is a rectifier circuit having a wide dynamic range according to an embodiment of the present invention, the illustrated; and

Figure 19 illustrates, a rectifier with a wide dynamic range based on quarter-wave transformers.

Detailed description of the preferred embodiments

An oversized matrix power amplifier in accordance with an embodiment of the present invention is illustrated in FIG. 4. A set of N input signals is connected to the input ports of an M + M port butler matrix 40 , selected according to Babcock or other optimal condition. To use the Babcock spacing, the ports of the Butler matrix are numbered with increasing integers, corresponding to the phase increments with which successive input signals appear in combination at the outputs.

For example, port 0 refers to the Butler matrix output corresponding to the sum of the input signals without phase shift. Port 1 refers to the output corresponding to the sum of input signals with an increasing phase shift in the row 0, dΦ, 2dΦ, 3dΦ etc. Port 2 corresponds to phase shifts 0, 2dΦ, 4dΦ, 6dΦ. . . etc. The M outputs of the Butler matrix 40 are amplified in nonlinear power amplifiers 42 . Amplifier outputs are combined using a similar Butler matrix 44 with M + M ports, and the N Babcock-spaced output ports provide desired amplified signals, while the remaining MN signals end in trivial loads 46 to impart unwanted cross-modulation as heat or energy dissipate.

An extreme case of the above occurs when the nonlinear power amplifiers 42 are saturated class C amplifiers. The output signal of a class C amplifier is characterized only by its current phase, so that the general problem can be formulated to find M phases that lead to the N arbitrary signals that are approximated as closely as possible, with cross modulation and distortion to MN closed ports. This problem is solved in the present invention by realizing that in order to define any N output signals, 2N degrees of freedom are necessary since the arbitrary signals have both a real and an imaginary part. Thus, if each input signal can only change in phase, it has only one degree of freedom, and 2N must be specified to synthesize any N signals.

As a result, it enables a 2N-channel matrix power amplifier ker with a Butler matrix with 2N + 2N ports that its Outputs combined that N amplified output signals exactly N of the output ports of the Butler matrix are reproduced,  with all cross modulation on the other N ports is collected, which end in irrelevant loads, vorge sets a method for deriving 2N in phase varying or constantly enveloping signals found can be, so that selected N combinations by the Butler matrix are generated, equal to the N desired Signals are.

One method is to have N configurations of constant amplitude to use the amplifier pairs to match each of the N signals to amplify varying amplitude. Each pair of amplifiers in this arrangement uses a pair of constant amplitude signals operated, with a medium phase that is equal to that of one desired signal, and a phase difference that is the same twice the ARCUS COSINUS the ratio of the momen tanen desired signal amplitude to their peak amplitude is. A hybrid connection can then be used to control the Sum and difference of the output signals of the amplifier pair form, the sum of which has the desired phase and amplitude and the difference ends in an irrelevant load or one Recovery technology for lost energy is subjected to which will be described below.

Fig. 5 illustrates a linear power amplifier, the class c is used, according to an embodiment of the present invention. A logarithmic amplifier / detector 21 can, if more convenient, operate at a lower intermediate frequency than that amplified by the power amplifiers. In this case, an optional step-up converter consisting of a local oscillator 53 , a mixer 54 and a selective filter 55 is used to convert the intermediate frequency to the final frequency. Otherwise the amplifier 21 can in principle work directly with the final frequency and the step-up converter 23 can be omitted.

The amplifier 21 is of a known type and produces a strictly limited output signal which receives phase information but whose amplitude variations are switched off. The amplitude variations of the input signal are encoded by the progressive detection process of the logarithmic amplifier into a signal which is proportional to the logarithm of the amplitude which, after optional low-pass filtering in the low-pass filter 60 , is given to a function generator. The function generator 62 converts the time-varying log amplitude signal into two time-varying signals labeled COSθ and SINθ to indicate that the sum of their squares is always 1. COSθ is equal to the ratio of the current amplitude to the peak amplitude, or, expressed in terms of log amplitudes, it is the number of the difference between the current log amplitude and the peak log amplitude. The peak log amplitude can either be determined by the function generator 62 over a sufficiently long period of time or can be set externally by means of a "SCALE" input. The SINθ function is only.

One way to implement such a function It is nerators to digitize LOG (A) and then digital sig nal processing circuits to use the function after hit tables include. Analog means can, however also used being diode or transistor networks are used, which is a piecewise linear approximation for synthesize the desired functions.

In the digital implementation, the LOGAMPLITUDEN signal taken off and digitized at a rate that is at least equal to the total signal bandwidth. The SCALE signal goes to the top of the LOGAMPLITUDEN signal set and subtracted from it to produce a value which is equal to the LOG of the ratio of the current to the Is peak amplitude. This value is always negative, can however, be complemented to a digital value  generate that is always positive. This binary value between 000. . . 000 and 111. . . 111 is then used as the address for one previously calculated table of corresponding cos (θ) and sin (θ) values are used. The values are precalculated, with the Formula θ = 2 ARCUS COSINUS [EXP (-λA)] is used, where A the address is and λ is a suitable scaling value, depending on the number of bits of the address, and their It is important to make the resulting θ value equal to that Twice the ARGUS COSINUS the ratio of the current to make the peak amplitude. The digital cos (θ) - and sin (θ) values are then converted into analog voltage waveforms converted using D / A converters and low pass filters will.

The COSθ and SINθ functions are used to multiply the constant amplitude signal provided by the logarithmic amplifier 50 , the low pass filter 51 and, if used, the up converter 52 . The multiplier 58 actually re-applies the amplitude modulation that was removed from the hard limiting amplifier 50 to the upper channel, while complementary amplitude modulation is applied to the lower channel so that the sum of the squares of the new amplitudes A1 and A2 Is one. This is done by selecting the functions COSθ and SINθ, whose sum square is automatically one. The new signals from multipliers 58 are A1 · EXP (jΦ) and A2 · EXP (jΦ), where Φ is the phase of the original input signal. These two signals are combined using a quadrature coupler 56 at the inputs of the class C power amplifier to produce (A1 + jA2) EXP (jΦ) and (A2 + jA1) EXP (jΦ). Since the sum of the squares of the real and imaginary parts thereof are one by design, the class C power amplifiers 57 receive constant amplitude driver signals so that they operate at maximum efficiency. The entire chain of components that has been described up to the quadrature coupler 56 is suitable for integration on a small, inexpensive silicon chip with a size of only 3 mm × 3 mm.

The two matched class C power amplifier stages 57 amplify their respective constant amplitude signals and recombine their outputs using the second one of the couplers 56 . One output of coupler 56 is GA1 · EXP (jΦ) while the other output of coupler 56 is GA2 · EXP (jΦ), where G is the gain. The first output is the desired output signal that represents the original input signal and its phase and amplitude variations. The second output is a lost energy signal that is either dissipated as heat in an insignificant load 61 or is subjected to the lost energy recovery process as described below. It will be understood that by using the above technique the peak power of the output signal is limited to the sum of the powers of the two class C power amplifiers 57 .

According to another embodiment of the present invention, N signals are defined which are the N + N port butler matrix combinations of N signals to be amplified. This can be done, if desired, by digital signal processing using a fast Walsh transform. Then each of the N transformed output signals is amplified by converting them into a pair of constant amplitude vectors using, for example, the technique illustrated in FIG. 5, which are amplified using 2N class C power amplifiers become. The 2N power amplifier outputs are then combined in pairs to produce N desired signals and N lost energy signals, and the N desired signals are recombined using an N + N port output butler matrix. The N lost energy signals can end in trivial loads that dissipate unwanted cross-modulation as heat, light or other electromagnetic radiation, or be subjected to a lost energy recovery process as will be described below.

The advantage of the above is that any signal at the output can temporarily reach a level equal to the sum of all 2N amplifier output powers if needed. This arrangement is shown in FIG. 6.

N input signals are combined in an N + N port input butler matrix 70 to produce N output signals. These are divided into DRIVER and COMPLEMENTARY DRIVER signals in driver signal dividers 71 , according to the procedure described above, so that each signal is a constant amplitude signal. These constant amplitude signals can be amplified with high efficiency by the N pairs of class C power amplifiers 72 , the outputs of which are then combined in pairs in combiners 73 to generate N desired signals and N signals of lost energy. The lost energy signals are dissipated as heat in trivial loads 74 while the N desired signals are recombined in the output Butler matrix 75 to produce the original N input signals at an amplified power level. As a result, undesirable cross-modulation products such as heat, light, or other electromagnetic radiation are dissipated in trivial loads 74 .

The combination of paired combiners 74 and the N + N port butler matrix 75 can be used as a 2N + 2N port combination network with 2N inputs (of the 2N class C power amplifiers 72 ) and 2N outputs (of which N end in trivial loads). It is actually a partial construction of a 2N + 2N port butler matrix that has been simplified by eliminating stages that only unnecessarily end the recombination of lost energy signals. In general, the combining 2N + 2N output matrix of such a device need not be a full Butler matrix, but can be simplified to its fast Walsh transformation equivalent by omitting fractional phase shifters or splitting into groups of smaller transformations. In general, it is desirable that at least the desired output signals be formed as combinations of all the power amplifier signals so that there is maximum flexibility to vary the output power of each signal up to the sum of all of the power amplifier's powers should this become necessary.

According to another embodiment of the present invention The process described above can be used to increase the output power in certain time slots, for the transmission of paging calls to mobile telephones used to increase the likelihood of reception increase.

In a TDMA system, every communication signal is one Part of a time multiplex frame duration, a time slot called, assigned to a general carrier frequency. In In a TDMA system, flexibility may be desirable to have the power level in certain time slots to raise. For example, a higher power level are needed to communicate with a mobile basic device adorn that temporarily under a signal attenuation due to Buildings, trees or any other object. A higher one Power levels may also be desirable in the time slots be used to transmit paging messages to mobile Devices are used to ensure reception when their antennas are in a retracted position.

This embodiment of the present invention has one Multiple satellite directional antenna to be the on earth  radiated area to divide into cells. A matrix power ver is stronger with an output corresponding to each antenna beam and consists of a variety of Power amplifiers using Butler matrices on their Outputs are connected to deliver each beam signal. Means are also provided for TDMA modulation to the Power level of the driver signals based on time to vary slot to slot. Facilities are too provided to transfer to groups of unused time slots to prevent any TDMA signal from being available Power amplifier power added during the period can be put in another beam by driving signals increase. The devices for TDMA modulation and the power changes are preferably arranged on the floor. A ground station shows the necessary signal generation for each beam signal and transmits it to the satellite. In addition, the matrix PA input Butler matrix com Binier can also preferably be arranged on the floor, so that the ground station already combined driver signals to direct driving each of the power amplifiers generated, and these signals become coherent to the satellite Transfer connections as described in the US patent application No. 08 / 179,983 entitled "A Cellular / Satellite Communications System With Improved Frequency Re-use (Ein Cellular / satellite communication system with improved Frequency Reuse) ", filed on January 11, 1994, open is beard, which is expressly incorporated by reference.

In the event that one or two time slots in each beam for a paging / call channel with higher performance than one If the traffic channel is assigned, the time slots become conscious staggered between the N different outputs, so that not two outputs in the same time slot high power request. In this way, a large increase in performance, about a factor of ten, in one signal path at a time can be achieved without too much of the total available power  subtract the power amplifier.

In the general formulation of the class C matrix power amplifiers, driver signals for 2N constant amplitude power amplifier stages should be constructed to include N signals with a desired amplitude and phase modulation at N of the output ports of a 2N + 2N port-output combination network and on Generate N lost energy signals at the other N output ports which can be dissipated as heat in trivial loads or subjected to a lost energy recovery process which will now be disclosed with reference to FIG. 7.

A fully general passive combining structure 80 combines the outputs of the 2N power amplifier stages 82 to produce N wanted signals and N unwanted signals that are dissipated as heat or light in trivial loads 81 . In a satellite application, the latter can be achieved by using filament lamps as the trivial loads, and the resulting light can be focused back on the solar cell array. The passive combining network can be the well-known butler matrix of the prior art, or a reduced butler matrix formed by omitting the combination of lost energy signals, or a simplified butler matrix according to a structure with a fast Walsh transformation in contrast to the usual FFT structure.

The general combining structure can be 2N by 2N Matrix with complex coefficients Cÿ are shown. The complex coefficients Cÿ describe both the phase and also the size of a signal voltage or current transmission from power amplifier number j to output port number i. Thus the N desired output signals can be expressed are considered, where GAIN is the expected gain through the Device is  

These equations have N complex (2N real) conditions that must be satisfied (the N real and N imaginary parts of the desired signals Si), and 2N degrees of freedom (the 2N phases θj). However, the nonlinear nature of these equations makes their direct solution to the phases jθ difficult. Instead, in the present invention, the equations are differentiated to obtain a set of linear equations for the changes in the phases Dθj required so that the desired signals Si are in from their previous values S (k-1) will change their new intended values S (k). So we get:

S (k) - S (k-1) = jGAIN * C * T * dT

where C is the abbreviation for the coefficient matrix, and T is the diagonal matrix

and dT is a vector of the 2N phase changes that were found should be.

If the product jGAIN · C · T is called a complex N by 2N matrix U and the difference between successive signal values S (k) -S (k-1) is dS , the following equation is obtained:

UdT = dS

The complex N by 2N matrix U can be considered a real 2N times 2N matrix are considered if the N × 2N real Coefficients URÿ with the N × 2N imaginary parts UIÿ after be nested in rows according to the following pattern:

Similarly, the N complex dS values include 2N real Values and can be as a real vector with 2N points be viewed in which real and imaginary parts are vertical are nested with each other. Thus the N are complex Equations U · dT = dS actually 2N real equations that in a simple way through a solution process for real ones Equations are solved and result

dT = U ^-1 · dS

The dT values found in this way are added to the corresponding θ values in order to obtain new θ values. These can be used to calculate new values for EXP (jθ), which are the required driver signals for the power amplifier. This conversion of θ values to driver signals can be done by simply supplying digitized θ values to a COS / SIN look-up table or ROM to obtain values for COS (θ) and SIN (θ) that are real and imaginary Are parts of EXP (jθ). The numerical values of DOS (θ) and SIN (θ) are then D / A converted and used to drive a quadrature modulator to generate the radio frequency drive signal as shown in Fig. 8, which will be explained in detail below . Since modern technology is able to build D / A converters of suitable precision (e.g. 8 bits) that can work with 1000 megam instantaneous values per second, a digital implementation can be used for practically all practical bandwidths.

The new θ values and the C matrix can be used to to calculate the S-values, which is actually through the lineari approximation of differentiation is achieved. As Alternatively, the S values achieved can be considered the desired ones Signal outputs are measured. They always are obtained values of S, which are used as S (k-1) the differences dS with the next desired set of To form instantaneous values S (k). Plant this way Errors do not continue and are limited. In the event that mes its S values from the next set of desired values S (k) the system can be subtracted as a Cartesian feedback be described with N channels. Cartesian feedback lung is a known technique for reducing distortion by using a quasi-linear power amplifier of a signal estimation demodulator to obtain the complex values of a signal at the output of a power ver to measure stronger and compare them with desired values to generate error values. The error values are integrated and fed into a quadrature modulator to create new ones To generate values of the power amplifier driver signals that will cause the power amplifier to more accurately provides the desired complex signal outputs. An advantageous The method for the above is in the US patent application No. 08 / 068,087 with the title "Selfadjusting Modulator (Selbstein providing modulator) "described herein by reference me is included. In the case of the above inventive Matrix power amplifiers are measured feedback complex values of the N output signals, so the next sentence to get complex values better, a form of Cartesian  Feedback to correct signal matrices instead of individual complex signal values.

By taking the new dS values in the manner described above are determined, the new θ values with the C matrix used to determine the new U matrix. A simplified The way to perform this function is to note that the effect of adding Dθ1 to Dθ2 will be to rotate the previous values of U1j by an angle Dθ1, what a transition of a fraction of their imaginary parts into their real parts and vice versa. For small values of Dθ enables this to update the U matrix without multiplication is lized. The Dθ values can always be kept small, by successive instantaneous values S (k-1), S (k), S (k + 1). . . be chosen that are sufficiently closely spaced in time are. A high speed digital logic machine or one Computer can be envisaged to do these calculations in Real time to perform continuous drive waveforms to the power amplifier stages of several MHz bandwidth give. Such a machine is for a satellite application preferably arranged on the floor, and the resulting Driver waveforms only become to the satellite above 2N alternately passed coherent feeder connections, as titled in U.S. Patent Application No. 08 / 179,953 "A Cellular / Satellite Communications System With Improved Frequency Re-use (A cellular / satellite communication system with improved frequency reuse) ", submitted on January 11, 1994, disclosed herein by reference is expressly included.

The arrangement for calculating the phase signals is illustrated in FIG. 8. A difference calculator 100 calculates the difference between the last approximation for the desired signals at time k-1 and the new instantaneous signal values Si at time k. The N complex differences are input to a matrix calculator 102 which multiplies them with an inverse U matrix to obtain 2N delta phase values. The delta phase values are collected in 2N phase accumulators 204 to generate 2N θ values that are converted to COSINUS and SINUS values using COS / SIN-ROMs 106 and then D / A converted using digital - Analog converter 108 can be used. The resulting 2N I, Q signals are passed to 2N quadrature modulators which apply the signals to the desired radio carrier frequency to obtain the EXP (jθ) signals shown in Fig. 7 for amplification by the constant amplitude power amplifier.

A simplified alternative is when the move on benden signals Si are radio signals that with digital information mation currents are modulated. When the information flows on each of the signal paths are symbol or bit synchronous, then the waveforms Si depend on one at all times limited number of past and future bits, according to the smearing caused by the impulse response of the Premodulation filtering is generated. The limit can be a S-value in the center of a symbol of at least only the symbol depend. With binary signaling, the signal can only do one of two values, 0 or 1, corresponding to a Si of +1 or -1 with suitable scaling to the desired one Output power and frequency. For a matrix power ver more limited size, for example with 16 channels, this means that there are only 2¹⁶ = 65536 different Vectors S can exist if the instantaneous value is bit-centered is taken. The 2N values of θ corresponding to each of these S Vectors can be pre-calculated and reasonably sized ROM can be saved and retrieved when they are needed by adding the current 16 bits to the 16 channels can be given as one address. For practical Purpose is to give the data transitions from one bit period to the next to control the spectrum can be obtained by using a smooth interpolation  Transition between these sets of θ values is made. So if a special θ value for one at present valid set of 16 bits that were transmitted was 130 degrees and a next value was -170 degrees, the θ value would be from old value to the new using the sequence 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, -175, -170 can be moved, note that the shortest route is taken. On The θ value that would have to move less far would become the same Take number of small steps. With every step the values THETA via COS / SIN-ROMs and D / A converter to one Quadrature modulator can be added to them in the desired radio frequency driver signals for the power amplifiers convert.

The general principle of the present invention for obtaining of multi-channel linear signal amplification, being nonlinear and even saturated power amplifier stages are used, is now along with a number of implementations have been described. The aim of the present invention, the To reduce transmission of unwanted cross-modulation signals like, due to the nonlinearities of the power amplifiers are generated by the selection of driver signals in a coupled power amplifier arrangement such he is enough that unwanted cross modulation on an output is directed, which is not for the desired signal transmission is used, the unwanted energy as heat or Light can be dissipated in a trivial load or subjected to a lost energy recovery procedure will.

In a further embodiment of the present invention, amplifier outputs are not combined before being fed to a multi-directional antenna, but instead are led directly to the elements of an antenna arrangement. Fig. 9 illustrates the use of a cylindrical array of slot antennas, such as could be used for a phased array base station, as described in US Patent Application No. 08 / 179,953 entitled "A Cellular / Satellite Communications System With Improved Frequency Re-use (A cellular / satellite communication system with improved frequency reuse) ", which is incorporated herein by reference. In such a phase arrangement, a number of antenna elements, such as 8 horizontal columns around the cylinder and 20 vertical columns, are used for sending or receiving signals from mobile radiotelephones. For transmission, the elements in each of the vertical columns can be driven in phase from the output of a single power amplifier using a 20-way passive power divider. Alternatively, each element can be equipped with its own smaller power amplifier (with 1/20 of the output power) and the 20 amplifiers in each column are driven in phase using the same driver signal.

Each column thus generates radiation in the vertical Level is focused, but still quite broad Azimuth is scattered. When the radiation from all eight Columns is calculated, however, by appropriate choice relative amplitude and phase between the eight columns that Focusing in the azimuth plane is also generated so that the horizontal radiation patterns narrowed and the directional gain kung is increased.

If any of the above arrangement for transfer multiple Signals each in a different desired Direction is used, the signal points for each column Sum of different signals with a suitable set of Amplitude and phase weights (complex values) for these Columns. For example, the signals S1, S2, S3. . . formed for the eight columns from the signals T1, T2, T3 which are transmitted as follows:

S1 = 0.5jT1 + (0.7 + 0.1j) T2
S2 = T1 + (0.6 + 0.3j) T2 + 0.5jT3
S3 = 0.5jT1 + (0.1 + 0.4j) T2 + T3 + (0.1 + 0.6j) T4
S4 = (-0.1-0.2j) T2 + 0.5jT3 + (0.9-0.1j) T4

etc., where j = a com changed phase by 90 degrees component.

It can be seen that the signal to be amplified Si for Application on a column of elements the complex weighted Sum of the independent signals T1, T2, etc. So must the amplifier or the amplifiers for the column reliably reproduce not just a single signal (the be a constant amplitude signal as with analog FM could), but the sum of independent signals, not one Constant amplitude signal. Thus is in the phase arrangement State-of-the-art base stations use of linear amplifiers that measure both the amplitude and phase reproduce variations of the composite driver signal ren, required. In U.S. Patent No. 3,917,998 to Welti, is the use of a coupled matrix of power ver stronger revealed, with the property that no one Amplifier must necessarily produce the peak power that require any antenna element or feeder may; however, the possibility of using Constant was amplitude power amplifiers not disclosed. At a previous embodiment of the present invention the possibility of using class C or constant amplitude power amplifiers in a coupled matrix by oversizing the matrix by a factor of at least two relative to the number of independently speci decorative amplified output signals that are desired. The previous embodiment consisted of a number of at least 2N class C power amplifiers, on their outputs gen coupled by an at least 2N + 2N port butler matrix or a lossless coupling network, the 2N Ein  gangsports with the amplifier outputs and N the output ports of the coupling network, which are the outputs for are the desired amplified signal, with the rest in irrelevant burdens ends. As a result, the unseen wanted cross modulation products in trivial loads dissipated as heat.

In the present embodiment of the present invention, the 2N + 2N butler matrix is not required. Instead, each column of elements in the array is split into even and odd elements numbered vertically from 1 at the top to at least 2N at the bottom. In an implementation of this embodiment, elements 1 , 3 , 5 , etc. of a column are connected by a passive N-way power divider, driven by a first power amplifier, while elements 2 , 4 , 6 , 8 ,. . . are connected by a second N-way power divider, which is driven by a second power amplifier. In a second implementation of the present embodiment, each element is equipped with a smaller power amplifier, and the amplifiers which are connected to even-numbered elements are all driven by a driver signal, while amplifiers which are connected to the odd-numbered elements all driven by a second driver signal. If the drive signals are the same, the radiation from the even and odd elements will increase in the horizontal plane, while if the drive signals are in anti-phase there will be no radiation in the horizontal plane. It is thus possible, by changing the relative phasing between in-phase and anti-phase, to produce changing amplitudes of the signal radiation in the horizontal plane, even if the individual elements of the column receive constant amplitude signals from their respective power amplifiers.

For the present invention, the invention  cellular base station at least one, but preferably one Number of such columns nested vertically Elements that are in cylindrical symmetry by 360 degrees of Azimuths on the top of an antenna tower or mast are arranged. The angular spacing of the columns is essentially chosen to the mechanical interference between them, however, can be greater than this minimum distance if this is a higher arrangement horizontal directivity there. As described below each column of elements must be fed with two signals become even-numbered and odd-numbered Amplify so that the ultimate horizontal radiation is equal to the desired composite signals Si that are defined above.

If the signal to be broadcast Si in column i as one amplitude A (t) changing over time and one changing over time changing phase Φ (t) is expressed, then

D1 = Ao · EXP [j (Φ + θ)]
D2 = Ao EXP [j (Φ-θ)

the temporally changing driver signals for the even number leaky and odd-numbered elements of column i, where

COS (θ) = A (t) / 2Ao.

It can be verified that when D1 and D2 add up to calculate the radiation in the horizontal plane Nope, we

D1 + D2 = Ao [EXP (j (Φ + Θ)) + EXP (j (Φ-Θ)]
= Ao · [EXP (jΘ) + EXP (-jΘ)] · EXP (jΦ)
= 2 Ao · COS (Θ · EXP (jΦ)
= 2 Ao (A (t) / 2 Ao) EXP (jΦ)
= A (t) EXP (jΦ)

received as requested.  

The principle of the present embodiment of the present invention can be extended by dividing a column of elements into four equal groups, ie Nrs. 1 , 5 , 9 . . . 2 , 6 , 10 . . . 3 , 7 , 11 . . . 4 , 8 , 12 , etc. Each group is connected to a single power amplifier for the group by means of a power divider or each element is equipped with its own power amplifier and the amplifiers of a group are driven in phase with a driver signal for each group is adjusted. Then a set of four drive signals is found so that desired signal radiation occurs at up to two desired elevation angles, which, if desired, can both be in the same horizontal plane. In general, the problem of how to generate radiation from N desired signals at N desired elevation angles from a column of at least 2N constant amplitude radiation elements can be solved by a mathematical process similar to that described above for generating N desired signals change the amplitude and phase is described, wherein at least 2N signals of constant amplitude and changing phase are used.

Thus, it has been shown above how each column of elements can be constructed in a cylindrical arrangement to provide a desired distribution for the radiation at a fixed elevation angle, e.g. B. in the horizon tal plane. It remains to be explained how the different contributions from each column are selected in order to focus the resulting radiation on the desired azimuth angle. This is done in a simple manner by arranging the radiation from the columns so that they would have the complex conjugate relationship to each other compared to signals that would be obtained from the desired azimuth. For example, if column 1 received a signal of amplitude 0.5 and phase 120 degrees from a mobile transmitter which is at 0 degrees azimuth, while column 2 would receive a signal of 0.7 and a phase of 50 degrees , that is, amplitudes with the ratio 0.5: 0.7 and phases that differ by -70 degrees, then column 1 and column 2 should produce radiation contributions in the same amplitude ratio 0.5: 0.7 for the transmission, however with a relative phase of +70 degrees.

The amplitude and phase relationship of the arrangement elements for the reception can be from the theoretical or measured polar Patterns of their constituent elements and their physical Arrangement in the group can be predicted. Thus, the relative phases and amplitudes for transmission in any direction by changing the sign of the Phases are predetermined. It is often sufficient that To quantify the number of possible directions to which the Arrangement can be set to a limited number of To transmit rays there, for example in 5 degrees-In intervals are spaced 360 degrees azimuth. The phase names Drawings and amplitude ratios can thus be for everyone of these 72 directions are calculated in advance. If the arrangement is formed from 8 columns of elements, there are white then an eightfold symmetry such that there are 72 possible Phase and amplitude relationships to only 9 different ones Reduce patterns that are repeated by the whole Pattern repeated in steps of a column around the arrangement becomes. It is therefore a relatively straightforward process, this 9th Store the pattern in a signal processor and the pattern and select the shift needed to make one given signal in a given direction to the next radiate 5 degrees. If this is for all signals has been performed, which is desired to abge radiate, and the results are summed up to the to set composite radiation from each column are to be generated by elements, the driver signals for the constant amplitude amplifiers that each column  are assigned, the method described above ren is used.

Fig. 10 is a block diagram illustrating a transmission signal processor which is designed so that it performs the process described above. A set of signals to be sent, T1, T2,. . ., Tn1, together with the assigned direction information θ1, θ2,. . . is sent to the transmit matrix processor 110 . The signals T1, T2, etc. are preferably in the form of a digitized instantaneous value stream, generated by (a) further signal processor (s) (not shown), which may include speech coding, error correction coding and digital conversion into modulated radio signal form . The latter represents each signal as a stream of complex instantaneous numerical values, with a real and an imaginary part or, alternatively, in polar form using a phase and amplitude. Matrix processor 110 uses directional information θ1, θ2, etc. to select or compute a set of complex weighted coefficients using stored data from memory 112 that is configured to configure the array. In its simplest form, the directional information θ1, θ2, etc. may consist of a beam number, and the beam number is used to select a set of previously calculated stored coefficients from memory 112 . The memories are used in complex multiplication with signals T1, T2 to give weighted sums S1, S2. . . etc. to generate.

The complex weighted coefficients are for each signal according to its desired radiation direction and under Using the principle of phase conjugation of the signals received from the desired direction, calculated how disclosed above. The weight coefficients can also be so be calculated that the transmission power is minimized, which is consumed to a given signal strength at the receiver  like to produce, as included in the US patent message No. 08 / 179.953 with the title "A Cellular / Satellite Communications System With Improved Frequency Re-use (Ein Cellular / satellite communication system with improved Frequency reuse) "is disclosed.

The number of sum signals generated is equal to the number of columns of arrangement elements, which may be greater than or less than the number of signals to be transmitted. Of course, the signals to be transmitted in the same direction at the same time are preferably modulated on different frequencies so that the same frequency is not used in the same number of beams more than once, except in a CDMA context. The frequencies of each signal are reflected in the nature of the modulated signals T1. Alternatively, the signals T1 may be nominally represented on a zero frequency carrier and the correct desired relative frequency, indicated within the matrix processor 110 , by including a phase increase during a snapshot process.

The composite output signals now represent the sum of the signals at different frequencies and are thus broadband signals with a correspondingly increased instantaneous value acquisition rate. Each signal Si is then converted into a pair of constant amplitude signals in driver signal dividers 114 , the sum of which has the desired instantaneous phase and amplitude of Si. This process of driver sharing is preferably carried out in the area of the digital signal, but shortly afterwards it is expedient to convert the driver signals into analog forms with the aid of D / A converters. Since the numerical form consists of complex numbers, one converter can be used for the real part and another for the imaginary part. The two signals generated are referred to in the prior art as I, Q signals and can be applied to a known quadrature modulator device in order to translate them into a desired radio frequency band. Via set signals are then amplified to a transmission power level, with powerful constant-amplitude power amplifiers 116 and 118 being used for even-numbered and odd-numbered column elements. These amplifiers can be distributed among the layout elements themselves.

It will be understood that the present invention can be found in similarly applied to arrangements of elements can be placed on a cylindrical surface, a flat one Surface or any other surface are arranged. The general principle is an abundance of elements of distinguish at least a factor of two from the number provide different signal directions, which is to dissolve the arrangement. In this way, the Arrangement when sending powerful constant amplitude lei have power amplifiers, and unwanted signal cross Modulation products that occur can be treated this way be that they are emitted in directions by which are different in which the arrangement the energy of the desired signals. For example, a orbiting satellite carrying such an arrangement, so can be designed in such a way that it connects the earth with the desired signals irradiated different locations during cross modulation products (unwanted signals) in the room without damage be emitted. In this application, the invention, those included in U.S. Patent Application No. 08 / 179,953 entitled "A Cellular / Satellite Communications System With Improved Frequency Re-use (A Cellular / Satellite Communication cation system with improved frequency reuse) "disclosed is used to generate the driver signals for the placement elements and associated amplifiers on the To place the floor, the resulting signals to the Satellites are sent using a coherent feeder link from a ground-based middle station. An advantage of the present invention is a reduction  the warmth that normally comes from a less effective linear power amplifier must be dissipated, so is designed to have such undesirable cross modulation signals not generated.

Another embodiment of the present invention concerns communication systems, which transmission stations used, and in particular systems in which the transfer a satellite orbiting the earth with a Communication responder is. This communication ant word device receives signal transmissions from a first one Ground station in a first frequency band, which is the feeder connection is called, and translates it into a second Frequency band called the downlink to a second ground base station that has a small, portable handheld station. The answering machine is still equipped with a variety of such channels, each with a transmit power amplifier and one Multiple directional antenna is connected. The invention used in combining network, like a butler matrix, around the multitude of power amplifiers with the multi-directional to connect the beam antenna so that each amplifier has one Part of each desired beam signal is amplified instead of that each amplifier is designed to be only one to amplify the desired beam signal.

In contrast to the prior art, an inverse Butler combination device at the first ground station used to get weighted sums of the desired beam signals for the answer to form, taking the power amplifier to be used. This has two advantages over the process the prior art of arranging the inverse Butler matrix in the satellite; first, the dynamic Reassignment of power between antenna beams without much Changes in the corresponding feeder connection signals be achieved; second, the pre-distortion of  Signals sent on the feeder connections used to partially map the distortion in Compensator to compensate for channel power amplifiers.

Additional benefits are seen in the preferred implementation by using a larger number of feeders connections and corresponding answering devices and channels and power amplifiers as the number of antenna beams given what a degree of redundancy against errors offers. The latter also enables distortion pro products towards the unused Butler Matrix outputs gangsports that end in trivial loads and are not connected to antenna beams.

The ability to emit heat from an orbiting satellite radiate can often be the predominant factor in limiting zen the capacity of a satellite communication system. Satellite communication systems that are designed so that they communicate with a large number of mobile stations deliver, are of the so-called multiple access type and can Frequency division multiple access, time division multiple access handle, code split multiple access or any Use a combination of these techniques. With FDMA or CDMA systems must have a large number of signals at the same time be emitted, leading to the problem of cross modulation in leads the transmitters. For TDMA signals there is a frame period divided into time slots and each signal occupies one Time slot. So it is not in a pure TDMA system necessary that many signals are emitted at the same time, and efficient constant amplitude transmitters be used. In practice, however, it requires an absence of an available frequency spectrum that a fourth multiple access method is also used, the space sharing lot subject access (SDMA) or "frequency reuse" is called. Frequency reuse is the well known technique for cellular Radiotelephones of dividing the earth into cells and enabling  Lichens that cells that are sufficiently separated are the same Use frequencies. Even if it is a satellite system If pure TDMA is used within each cell, it can be SDMA must use to allow other cells to use the same Use frequency; thus the satellite finally ends doing that he was taking different signals at the same time in under must send out in different directions. The one described above Invention can be used to enable a phase-controlled arrangement of antenna elements with assigned effective class C power amplifiers a number of TDMA signals for immediate radiation in different generated directions. The amount of directions can vary change from one time slot to the next as in the U.S. Patent Application No. 08 / 179,953 entitled "A Cellu lar / Satellite Communications System With Improved Frequency Re-use (A cellular / satellite communication system with improved frequency reuse) ". The total efficiency of such an inventive arrangement, out expresses in quantities of conversion of direct current energy a solar array or a battery in useful abge radiated signal energy should not be greater than if one Prior art arrangement using linear amplifiers has been used. However, the missing one shows up Efficiency less in terms of heat dissipation and instead of than the harmless radiation of radio energy in the form of Cross modulation products in the room. As an alternative you can cross-modulation of the recovery described herein procedure for lost energy.

TDMA is a preferred choice for such a responder because a communication system is often less than 100% loaded is. In the TDMA case, the responder according to the invention with maximum efficiency for active time slots operated and is switched off for time slots that against are not currently being used. To achieve this, the Traffic is preferably sorted so that it gets as far as possible  all rays use the same active time slot, which ensures that the same time slots on each beam are not active. The entire transponder arrangement can then for time slots in the power that are shut down are not active for all beams. For time slots on many, but not inactive on all rays, it can be efficient, only certain arrangement elements in the lei to go down and make sure that the others do maximum output to be operated to the other rays support, thus reducing heat dissipation to a minimum reduced.

In its simplest form, this advantage of the present invention can be obtained using the arrangement of FIG. 11. A pair of efficient constant amplitude power amplifiers 122 and 124 amplify signals that are either generated by driver distributor 120 or obtained separately from the ground via two coherent feeder connections. A hybrid connection 126 combines the output signals from the power amplifiers to generate a sum signal and a difference signal. The driver signals can be provided so that either the sum or the difference signal is the desired signal. In Fig. 11, the sum signal is desired and is connected to an antenna 130 , such as a horn, which irradiates the desired target area, ie the earth. The difference signal then contains undesired cross-modulation products. In systems of the prior art, the difference signal has been dissipated as heat in an irrelevant load. However, the present invention provides maximum heat reduction by instead radiating the lost energy into the room by using a separate directional antenna 128 pointing away from the earth. The simplest form of the invention can of course be extended in an obvious manner to multichannel response devices that have many rays that point to the earth and dissipation rays for lost energy that point away from the earth. As an alternative, the differential signal can be rectified using the rectifier according to the invention of Fig. 18 or 19, and the lost energy can be returned to the battery. All such arrangements are considered to be within the spirit and scope of the present invention as described by the following claims.

Another embodiment of the present invention relates to recovering lost energy generated in a power amplifier. In Fig. 12, a power amplifier 140 by an isolator / circulator 141, and an optional transmit filter 142 is coupled to an antenna 143rd In duplex systems that require simultaneous transmission and reception on different frequencies, the transmission filter can form part of the antenna duplex filter, the other part of filter 144 being associated with the receiver. With non-duplex systems, such as the time division duplex / time division multiple access systems or simply with intercom systems, this need not be a duplex filter, but instead a transmit / receive antenna switch. The present invention is applicable to both of these configurations. In the present invention, the trivial load that is normally connected to the circulator's reflected power port is replaced by a rectifier 145 . Rectifier 145 converts AC radio frequency energy to DC, which is then returned to the battery or power source that provides power to the transmitter. If the efficiency of the transmitter is E1 and the efficiency of the rectifier is E2, then a fraction E1 · E2 of the total energy will be recovered in the case when the antenna is completely mismatched, reflecting all of the transmitted power that has been applied to it . The fraction E1 · E2 can of course never be greater than one. In the event that the antenna reflects a fraction R of the input power, the final energy consumption will be reduced by the factor 1-R · ER1 · E2. For example, if R = 10%, El = 55% and E2 = 70%, the battery consumption will be reduced by 3.85%, which is a considerable saving. When the effective energy is calculated as the ratio of the power actually radiated from the antenna to the final energy consumption, the efficiency curves with and without using the present invention are drawn as in FIG. 13. Figure 13 shows that the effective efficiency is less sensitive to antenna mismatch when the present invention is used. Fig. 14 shows the percentage of increased talk time indicated by using the present invention as a function of the percentage of reflected energy from the antenna.

Another embodiment of the present invention is illustrated in FIG. 15. Two similar power amplifier stages 150 and 152 are combined using a 3 dB directional coupler 154 to obtain the sum of their output powers on antenna 156 . An unwanted differential signal is generated which, instead of being dissipated in an insignificant load as in Fig. 2, is converted to a direct current in the rectifier 158 and the current is returned to the battery or power source that powers the amplifiers. The same curves illustrated in Figures 13 and 14 apply equally to this embodiment.

Another embodiment of the present invention is illustrated in connection with the controlled linearization (feed-forward-line arization) of the power amplifiers. Controlled linearization is used to improve linearity over what can be achieved with simple amplifiers, or to obtain improved efficiency for a given linearity. A controlled amplifier with improved efficiency is illustrated in FIG. 16, and the main amplifier 160 may be a class C amplifier that generates a constant amplitude signal. If a higher amplitude is currently required, an error amplifier 162 generates an output signal which is added to the output signal of the class C amplifier 160 in a directional coupler 164 . If a low amplitude is currently desired, the phase of the error signal is reversed, causing the error signal at the main output 166 to be subtracted in the directional coupler 164 , increasing the level of the difference signal 168 . Normally, the energy in the differential signal will dissipate and be lost in an insignificant load. However, the present invention uses a rectifier 170 to convert the differential signal into a direct current that is returned to the battery so that the energy is recovered. The size of the error amplifier 162 with respect to the main amplifier 160 and the selection of the coupling ratio of the directional coupler 164 for the maximum overall efficiency must be carried out with the knowledge of the signal amplitude statistics.

Without the present invention, the efficiency is given by:

in which
k is the voltage coupling factor of the directional coupler 164 ,
Ec is the efficiency of amplifier 160
EL is the efficiency of amplifier 162 at its maximum output amplitude Bpk,
A is the constant signal amplitude generated by amplifier 160
B is the difference between A and the desired output signal waveform that must be contributed by amplifier 162 ,
Bpk is the peak amplitude of signal waveform B, and the sweep means the mean over time.

When the present invention is used, the effective efficiency given by:

where R is the efficiency of the rectifier and D is the Difference is given by

D = k (A + B) -B / k.

Another embodiment of the present invention concerns the recovery of lost energy in Hochlei base station transmitters for multi-carrier operation. If it is required that a cellular base station has many sub positions with mobile stations on different frequencies Zen supported is the first choice for the transmitter design between a single high-performance multi-carrier line power amplifiers and a variety of low power Single carrier amplifiers. The multi-carrier amplifier must be linear and is very inefficient because of the high peak Average ratio of the composite multi-carrier signal. In the event that the controlled linearization is used, the present invention can be used to recover lost Withdraw energy from the differential port of an output coupler win.

If a single carrier amplifier approach is chosen, one Facility to be made available to the variety of Connect amplifiers to the antenna. Multiple antennas are not cheap because they are rather big and expensive and a lot Need floor space. One way multiple amplifiers with the To couple antenna, is to use a multi-coupling filter use the frequency selectivity used to the under  isolate different amplifiers. Vielkopp Lung filters are large and expensive and are only feasible if the Frequency difference between the multiple carriers does not increase is small. The alternative is to combine dissipative use, where amplifiers are combined in pairs, using hybrid couplers or directional couplers that are essentially sum and difference networks. At Using dissipative combining for two signals is used Example of a 2P power amplifier for a first signal and a second power amplifier the off gear power 2P used for a second signal. The Outputs of the two power amplifiers are then under Combined using a 3 dB coupler. The coupler allows it that half the power of each power amplifier, d. H. P from any power amplifier that reaches the antenna while the other half is usually in an insignificant Load is dissipated. Generally this requires dissipative Combine N signals that each signal has a power is amplified, which is N times the desired power P is, so that the total power of all N amplifiers N × NP where only NP (P from each amplifier) is the antenna reached. If N is a power of 2, it is dissipative A binary tree combiner that combines pairs of signals and then pairs of pairs, etc. until the final Output. Each pair-combining network can be one 3 dB coupler.

With each coupler, half of the power is extracted into a sum signal and passed to the next coupler or the final output, while the other half is normally lost in an irrelevant load. Thus, half of the total power is wasted when combining two beams, 3/4 of the total power is wasted when combining four beams, and generally a fraction of (N-1) / N of total power is wasted when N beams are combined. By using the present invention, this normally lost power is recovered at least to the extent of rectifier efficiency R. Thus, instead of the final efficiency being only E / N, where E is the efficiency of a single carrier power amplifier, the effective efficiency is E / (N- (N-1) E · R). For example, when E = 60% and R = 70%, the effective efficiency versus N in Figure 17 is plotted with and without the present invention. The figure illustrates that efficiency can be improved by a factor of more than 1.5 using the present invention.

In the case of multi-carrier transmitters, it is generally desired that Minimize generation of unwanted frequency components that by cross-modulation between the carrier frequencies will call. These components occur at frequencies like 2f1-f2 or 2f2-f1 on if the hybrid coupler is not perfect Isolate the transmitter on f1 from the transmitter on f2. However, can including a rectifier on the differential port of the coupler, if no care is taken, strongly to that Generation of cross modulation components contribute. This Problem refers to the more general problem, such as a Rectifier to be generated from the energy of one AC voltage source with variable voltage on a fixed DC voltage should transmit. Of course it's a solution that can be used to turn on a regulator, preferably one of the pulse width modulation type, i.e. H. Switching mode type, between the variable DC voltage output of the Amplifier and the fixed voltage to which it is connected shall be. However, an alternative and new solution is below which does not use an active circuit.

Fig. 18 illustrates a rectifying circuit with a wide dynamic range with a cascade of diode rectifier stages, each stage consists of a quadrature coupler ler, which drives a pair of identical diode rectifiers, and preferably full-wave rectifier. A quadrature coupler has the property that when it ends with two identical load impedances, any energy reflected from a load impedance mismatch is output to the so-called isolated port and is not returned to the source. The AC load impedance shown by each full wave rectifier is actually equal to the DC load impedance, which in turn is equal to the output voltage, i.e. the fixed supply voltage to which the rectified energy is to be returned divided by the rectified current . Since the rectified current changes with the AC signal amplitude while the output voltage is forced to a fixed value, the rectifier is a variable load impedance which therefore does not match the source, causing inefficiency and cross-modulation. However, in the new configuration illustrated in FIG. 18, the reflected power when the rectifier load deviates from a perfect match is transmitted to the isolated port and not returned to the source. As a result, this energy has a second opportunity to be recovered in the second stage rectifier, and so on. By switching each rectifier stage so that it is efficient at the level of residual power supplied to it by a previous stage, the ultimate reflective effect of the cascade of amplifiers is the product of that of the individual stages, ensuring that all are in question standing power level of the source little energy is reflected and that the vast majority is rectified and transferred to the fixed voltage level. This new rectifier circuit thus adapts a variable voltage AC source to a fixed DC voltage without the use of active regulators.

Other designs of such rectifiers can also be built. For example, another embodiment of the present invention is illustrated in FIG. 19. A first rectifier stage 200 is connected via a quarter-wave transformer 202 03297 00070 552 001000280000000200012000285910318600040 0002019549357 00004 03178 to the near end of a transmission line 204 and is matched to the source impedance. By selecting the matching transformer 202, this first rectifier is adapted to efficiently rectify small signals. For larger signals, the rectifier shows a reduced impedance, which translates into an increased impedance at the connection of 202 and 204 , because of the reciprocal impedance transformation, which is carried out by a quarter-wave transformer. Thus, with a larger signal, the first rectifier does not stress the transmission line 204 so much. A second rectifier stage 206 is connected via a second quarter-wave matching transformer 208 to a point a quarter wavelength downstream on the transmission line 204 . This second amplifier is adapted to be below the rectification threshold for the small signal levels to which the first rectifier is adapted. Thus, it shows a high impedance for the second quarter-wave matching transformer 208 , which translates into a low impedance at the connection of 208 and 204 . A quarter wavelength closer to the source when connecting 204 and 202 translates this back into a high impedance, which therefore does not burden the rectifier 200 . As a result, the source energy is primarily absorbed by rectifier 200 at low signal levels and primarily by rectifier 206 at high signal levels. The principle can be expanded by adding more rectifiers, with associated matching transformers, progressing at 1/4 wavelength increments down transmission line 204 to produce a rectifier device that converts energy from an AC source of any voltage level to a fixed DC voltage. One of ordinary skill in the art will also recognize that discrete component equivalents of the disclosed transmission line or coupler networks can be constructed, as well as waveguide circuits or circuits that use circulators to achieve the same goal, and all such constructions that adapt a variable voltage AC source to a fixed one DC voltage levels are considered to fall within the scope of the relevant invention.

It will be appreciated by those of ordinary skill in the art that the present invention in other specific forms can be embodied without distance from the thought or essential character. The embodiment disclosed herein Forms of development are thus illustrated in all respects considered and not limiting. The scope of the inven dung is by the appended claims instead of by given previous description, and any changes get into the meaning and range of equivalences in it should be included in it.

Claims (15)

1. A method of reducing lost energy in a communication system using a first station with a first plurality of second stations using a phased array antenna, comprising the steps of:
Generating the first plurality of signals for transmission to the second stations using radio wave modulation;
Combining the first plurality of signals to produce a second plurality of signals, the combined signals being complex weighted sums of the first plurality of signals, the second plurality corresponding to a number of antenna elements arranged along a first dimension of the phased array ;
Generating a third plurality of signals from the second plurality of signals corresponding to different groups of elements arranged along a second dimension of the phased array;
Amplifying the third plurality of signals to produce desired and undesired signals; and
Radiate the desired signals in desired directions and the unwanted signals in other directions. 2. The method of claim 1, wherein the first station is a orbiting spacecraft. 3. The method of claim 1, wherein the antenna Directional antenna is. 4. The method of claim 2, wherein the antenna Directional antenna with at least one directional beam, that points away from the earth. 5. The method of claim 2, wherein the radio waves modulation the speech coding, error correction code coding, error detection coding and time division Multiplex or digital modulation includes.   6. A communication system using a first station with a first plurality of second stations using a phased array antenna, with:
a signal generator for generating the first plurality of signals for transmission to respective second stations using radio wave modulation;
a combiner for generating a second plurality of combined signals that are complex weighted sums of the first plurality of signals, the second plurality corresponding to a number of antenna array elements arranged along a first dimension of the phased array;
driver signal generating means for generating from each of the second plurality of signals, a third plurality of signals, corresponding to the different groups of elements arranged along a second dimension of the phased array;
an amplifier device for amplifying the third plurality of signals using respective transmit power amplifiers which are adapted to transmit constant amplitude signals with high efficiency; and
an antenna device which is connected to the amplifier so that desired signals are radiated in desired directions and undesired signals are dissipated in other directions. 7. The method of claim 6, wherein the first station is a orbiting spacecraft.   8. The method of claim 6, wherein the antenna is a Directional antenna is. 9. The method of claim 6, wherein the antenna Directional antenna is, with at least one beam gone from earth shows. 10. The method according to claim 6, wherein the radio waves modulation speech coding, error correction coding, Error detection coding and time division multiplexing or Includes digital modulation. 11. Communication system using a first station with a first plurality of second stations, using a phase controlled array antenna, with:
a signal generator for generating the first plurality of signals for transmission to respective second stations using radio wave modulation;
signal processing means for processing the first plurality of signals to generate a second plurality of constant amplitude drive signals;
an amplifier device for amplifying the second plurality of driver signals using transmit power amplifiers adapted to transmit constant amplitude signals with high efficiency; and
an antenna device which is connected to the amplifier device for radiating the power amplified signals in such a way that desired signals are emitted in desired directions and undesired signals are dissipated in other directions. 12. The system of claim 11, wherein the first station is a Cellular radiotelephone base station is one with a Switching center is connected. 13. The system of claim 11, wherein the second stations are portable or portable wireless phones. 14. The system of claim 11, wherein the radio wave modules tion the speech coding, error correction coding, Error detection coding and time division multiplexing or Includes digital modulation. 15. Satellite communication system for communicating from at least one ground station via at least one orbiting satellite with a plurality of mobile stations, with:
signal generating means for generating a plurality of constant amplitude signals in response to signals which are desired to be relayed to the mobile stations;
a power amplifier device configured to amplify the constant amplitude signals to produce desired and undesired signals; and
an antenna device which is coupled to the power amplifier device so that desired signals are emitted in the direction of the mobile stations and the undesired signals which have been generated by the signal generator and power amplifier device are emitted in other directions.