KR100804201B1 - Delay equalization in wireless communication systems having a highly selective filter - Google Patents

Abstract

A receive front end for efficient reception of a communication signal includes a band pass filter having a high selectivity for selecting a pass band of the communication signal; An equalizer for compensating for group delay variation caused by the high selectivity ratio of the bandpass filter; And a low noise amplifier protected by signals outside the pass band by a band pass filter and coupled to the equalizer to determine the noise shape of the receive front end, wherein the band pass filter and the equalizer include a high temperature superconducting element, and a band pass filter The equalizer and low noise amplifier are characterized in that they are arranged in a cryostat for operation in a low temperature environment.

HTS

Description

DELAY EQUALIZATION IN WIRELESS COMMUNICATION SYSTEMS HAVING A HIGHLY SELECTIVE FILTER}

1 is a block diagram of a schematic receive shear of the present invention

Figure 2 is a block diagram showing an equalizer of the receiving shear of Figure 1 according to an embodiment of the present invention

3A and 3B are schematic perspective views of the equalizer of FIG.

4 is a block diagram showing a pre-selection filter of the receive front end of FIG.

5 is a block diagram showing the configuration of the pre-selection self-equalization of the receive front end of FIG.

6A and 6B are schematic perspective views of self-equalization of the pre-selection filter of FIG. 5 in accordance with an embodiment of the present invention.

FIG. 7 is a perspective view of a self equalizing unit of the pre-selection filter of FIGS. 5, 6A, and 6B.

8 is a self-illuminated cross-sectional view of the pre-selection filter of FIG. 5 along line 8-8 of FIG. 7.

Explanation of symbols for the main parts of the drawings

10. Receive shear 12. Antenna

14. Cable 16. Cabinet                 

18. Output port 20. Cold holding device

22. Bandpass Filter 24. Low Noise Amplifier

26. Equalizer

The present invention relates to a wireless communication system and, more particularly, to a wireless communication system for addressing delay equalization with respect to a high selection filter.

High frequency receivers for wireless communication stations must be provided with both high sensitivity (the ability to receive weak signals) and selectivity (the ability to differentiate between signals separated by small frequency differences) in an increasingly opposing frequency spectrum. . In a typical base station, the received high frequency signal first passes through a low loss high frequency band pass filter to remove signal elements outside the frequency range of the desired signal.

delete

Because the filtered signal is so weak, it is coupled to an amplifier (ie, a low noise amplifier or LNA) that does not reflect a large amount of noise, such as a low noise amplifier.

Recently, superconducting technology has been advanced, and a new type of RF filter called a high-temperature superconducting (HTS) filter is emerging. High temperature superconducting filters include components that act as superconductors at or above the liquefaction temperature of 77 K of nitrogen. These filters offer significantly increased performance in both sensitivity and selectivity over conventional filters that are not superconducting. In particular, high temperature superconducting filters are known to provide superior performance with smaller signal losses than is possible with the use of conventional filters. The enhancement of selectivity without high insertion loss generally allows wireless communication carriers to increase the area of each base station. Increased ranges will increase the minutes of use (MOUs) while the system remains within their tolerances.

delete

delete

delete

delete

However, these advanced capabilities further complicate the system of the components of each RF receiver and increase manufacturing costs. In particular, high temperature superconducting filters must be added with a filter cooling system that maintains a relatively low temperature (eg, approximately 90 K or lower).

delete

In order to keep the device at such a temperature, the cooling system includes several types of cryorefrigerators. Cold chillers typically include a compressor and a heat exchanger or cold head to maintain a supply of compressed coolant to remove heat from the devices to be cooled. In addition, the high temperature superconducting filter should minimize the amount of heat transfer from the surroundings by placing the cooled devices in a cryostat. The cryostat frequently discharges any gaseous material to reduce heating by convection.

delete

Systems that use high select filters for group or envelope delays present complex problems. In general, an ideal RF filter has a constant group delay for all frequencies in the passband. In this way, signals in the pass band arrive at the filter output without phase distortion between different frequencies. However, filters used in satellite communications (i.e., C and X-band signals) present a need for compensation for delay equalization or phase nonlinearity propagated into the generally speaking pass band. In contrast, delay equalization in conjunction with amplitude compensation is addressed at baseband frequencies after demodulation of carrier frequencies in a wireless communication system.

delete

delete

delete

One method of correcting phase distortion is to use a delay equalizer (hereinafter, equalizer), which is a prepass transfer function (pass) that compensates for the nonlinear effects of the filter to equalize the delay for all frequencies in the passband. Distortion is typically compensated by providing an amplitude of any one of all frequencies in the band). For example, nonlinearity is compensated by designing an equalizer with a transfer function with appropriately positioned complex zeros to counteract the effect of the polarity of the filter.

delete

Typical equalizers include a circulator with an input port, a second port coupled to a one-port network, and an output port. The circulator represents a passive waveguide junction for passing signals in a single direction from the input port to the second port and from the second port to the output port.
However, general equalizers are not suitable for the use of high temperature superconducting filters that have recently been coupled to wireless communication stations for some reason. Since filters induce RF delays in proportion to rejection, the use of high-selective high temperature superconducting (HTS) filters presents more extreme equalization requirements than previously encountered, among other things, design complexity. And tuning saturation come to the fore. Moreover, common equalizers will be incompatible with the low temperature environment imposed by the high temperature superconducting filter and / or the stringent tuning and other requirements imposed by the high temperature superconducting filter in particular.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem of the prior art, and to provide a wireless communication system for delay equalization addressing for a high selection filter in a wireless communication system.

delete

delete

delete

According to the present invention, a receive front end for efficient reception of a communication signal includes a bandpass filter having a high selectivity for selecting a passband of the communication signal and an equalizer for compensating group delay variation caused by the high selectivity of the bandpass filter. And a low noise amplifier coupled to the equalizer to set the noise shape of the receive front end and protected by a band pass filter from signals outside the pass band.

In a preferred embodiment, the band pass filter comprises a high temperature superconducting element and the equalizer further comprises a high temperature superconducting element. Band pass filters, equalizers and low noise amplifiers are disposed in cryostats for operation in low temperature environments.

Receive filters may be useful in connection with other types of wireless communication systems such that each communication signal comprises a PCS signal or a cellular signal.

Preferably the equalizer comprises a plurality of resonators. The equalizer includes a housing defining a plurality of cavities in which the plurality of resonators are located. The plurality of resonators includes a pair of discontinuous resonators coupled adjacent to each other. The equalizer preferably includes a high-light external equalizer.

In another preferred embodiment, the band pass filter comprises a magnetic equalization filter. Preferably the receive shear comprises a low temperature vessel in which a magnetic equalization filter is located. The magnetic equalization filter includes a high temperature superconducting element. The equalizer also includes additional high temperature superconducting elements.

According to another aspect of the invention, a receive front end for receiving a communication signal comprises a plurality of steps combined for setting of complex zeros for delay compensation within a pass band of the communication signal and selecting a pass band of the communication signal. An equalizer is coupled to the high selection band pass filter to include a high selection band pass filter and to further provide delay compensation within the pass band of the communication signal.

In a preferred embodiment, the highly selective band pass filter and equalizer comprise a high temperature superconducting element. The receive front end further includes a low noise amplifier connected to the equalizer to set the noise shape at the receive front end and protected by a high selection band pass filter from signals outside the pass band. High selection bandpass filters, equalizers and low noise amplifiers are placed in cryostats for operation in low temperature environments.

The equalizer preferably comprises cavities defined by the housing of the equalizer, a plurality of resonators respectively disposed in the plurality of cavities. The plurality of resonators includes a pair of discontinuous resonators coupled to each other. A pair of discontinuous resonators are adjacent to each other.

According to another aspect of the invention, a band pass filter having a pass band comprises a plurality of resonators, each resonator comprising a high temperature superconducting material. The plurality of resonators includes a pair of discontinuous resonators, and the pair of discontinuous resonators are coupled for setting of complex zeros for delay compensation in the pass band.

The plurality of resonators are arranged such that a pair of discontinuous resonators are adjacent. The band pass filter includes a housing in which a plurality of cavities are defined and the plurality of resonators are each disposed in the plurality of cavities. The housing includes a wall separating the pair of discontinuous resonators, and the wall includes a hole for cross coupling the pair of discontinuous resonators.

In one embodiment, the band pass filter is combined with an equalizer coupled to the band pass filter to provide additional delay compensation. The equalizer further includes a low noise amplifier that includes a high temperature superconducting element and couples a band pass filter to the equalizer for setting of the noise form regarding the combination. The equalizer may be a high efficiency equalizer and / or multiple resonant device. The multiple resonant device may comprise a housing defining a plurality of cavities and may further comprise at least two discontinuous resonators coupled to each other. Two discontinuous resonators may be adjacent.

Other features and advantages will be apparent to those of ordinary skill in the art from the detailed descriptions inherent in the claimed filters and receive shears or in connection with the accompanying drawings.

The present invention seeks to compensate for group delay variations caused by one or more high-selection filters at the receive front end of a wireless communication system. Delay compensation in accordance with the present invention includes any internal equalization, external equalization or some combination thereof.

In particular, delay compensation at a receive front end with a high select filter may include an improved magnetic equalization filter, an external equalizer or a combination thereof.

1, a base station or some other communication station for the transmission and reception of a communication signal comprises a receiver, and then the receiver generally comprises a front end (hereinafter referred to as a receiver front end) generally indicated by 10. The antenna 12 is coupled with the receive front end 10 via coaxial cable or other cable 14 with a suitable impedance or other type of connection known in the art. The receive front end 10 may be received in a cabinet 16 having an output port 18 that maintains connection with the components of the receiver. The cabinet 16 includes components other than those belonging to the receive front end 10, such as a transfer filter, and may further include additional systems for forming a multiple signal path. The receive front end 10 may also be coupled with a duplexer configuration in which components in the delivery path are packaged and / or shared with the components in the receive path. It should be noted that one or more antennas (whether or not omnidirectional as known in the art) may be connected to the receive front end 10 for the service area of a multi-sector cell.

delete

delete

delete

delete

For simplicity of the description, the present invention discloses only a receive, single cell or sector environment, although certain elements, aspects or components to be described below may be duplicated, combined or changed for the operation of a multi-sector environment, a transmitter. Will be understood.

According to a particular embodiment of the invention, cabinet 16 includes a cryostat 20 for maintaining a low temperature environment of components disposed therein. The cryostat 20 may be a thin walled cryostat, such as the device disclosed in the currently pending US patent application Ser. No. 08 / 831,175, incorporated herein by reference, or other suitable for setting a constant temperature and pressure environment. It may be a cryostat. Finally, the cryostat 20 is coupled to a cryo freezer (not shown).

delete

delete

According to one embodiment of the invention, the cryostat 20 is preferably some low temperature comprising a preselection, a band pass filter (hereinafter filter) 22, a low noise amplifier 24 and an equalizer 26. Accommodate components that need it. The filter 22 is coupled to an input port 28 for receiving a communication signal collected by the antenna 12 and transmitted by the coaxial cable 14 to the receive front end 10. The filter 22 is typically designed to protect the low noise amplifier 24 from signals outside the pass band of interest of the wireless communication system collected by the antenna 12. Next, the low noise amplifier 24 is designed to enhance the signal at frequencies within the passband of the filter without the addition of any significant noise, whereby the noise shape for the receive front end 10 is obtained or determined. The filtered and amplified communication signal improved by the filter 22 and the low noise amplifier 24 is fed to an equalizer 26 designed to compensate for group delay variations caused by the filter 22 in the pass band.

delete

delete

delete

delete

The filter 22 may be a filter system in view of the fact that multiple filters are connected in series to provide higher reflectivity. The filters may be separated by an isolator or other buffer or amplifier described in US patent application Ser. No. 09 / 130,274 of the currently pending co-pending application incorporated herein by reference. In view of the fact that filter 22 comprises a resonator or other components with HTS material, irrespective of the particular shape, filter or filters 22 are preferably HTS based filters. The filter 22 more preferably includes multiple cavity resonators using high temperature superconducting (HTS) materials to provide excellent rejection while maintaining extremely low insertion loss. In particular, such high temperature superconducting filters may comprise one or more components on which a high temperature superconducting material is thick coated. Suitable high temperature superconducting filters have been available from the Illinois Superconductor Corporation (Illinois Prospect Material) for many cellular and PCS bands, and are a combination of low noise amplifiers in stacked devices used with the Spectrum Master and Range Master trademarks. Can be obtained.

delete

delete

delete

delete

delete

Other high temperature and non-temperature superconducting filters suitable for the practice of the present invention are further described in the above-mentioned applications, or will be described in more detail below.

It should be noted that the filter 22 need not include thick film resonators or cavity based resonators, but may be based on thin film superconducting material deposited on a suitable substrate to be disposed within the resonant cavity. Filter 22 may also constitute a dual mode, all temperature filter, as disclosed in the currently pending US Patent No. 09 / 158,631, incorporated herein by reference. Such dual mode filters provide continuous operation while the power supply is interrupted as a result of operating temperatures above the critical temperature of the superconducting material.

delete

delete

Other types of high select filters can be used in place of high temperature superconducting filters to provide high rejection with low insertion loss. For example, filters including components made of non-superconducting ceramics with low noise floors, as well as non-superconducting filters that provide improved response in operation in low temperature environments, are already known in the art. have. Regardless of the material of the filter, as used herein, a high selector filter (or optionally a filter with high selectivity) has 10 or more poles for a bandwidth of approximately 1% or more (typical full or full-band systems). Configure filters with five or more poles for filters or bandwidth of approximately 0.3% or less (individual channel systems). More preferably, filter 22 has 12 or more poles for approximately 1% or more bandwidth, while filter 22 has 6 or more poles for less than 0.3% of bandwidth. Most preferably, filter 22 has 16 or more poles for approximately 1% or more bandwidth, while filter 22 has 8 or more poles for approximately 0.3% or less of bandwidth.

delete

delete

delete

delete

The high temperature superconducting filter or other high select filter 22 preferably has a cumulative noise contribution of 1 dB or less, preferably about 0.7 dB or less and more preferably 0.5 dB or less. It should be noted that the type of noise described above is of course temperature dependent and may require adjustment for it.

delete

The filters 22 are each connected to the low noise amplifier 24 via 50 kHz coaxial cable or other suitable transmission line known in the art. The transmission line must be impedance matched to filter 22 and low noise amplifier 24 to prevent reflection and hence signal loss. The low noise amplifier 24 outputs a filtered and amplified RF signal with a fixed magnitude gain throughout the frequency range corresponding to the pass band of the filter 22. For example, the low noise amplifier 24 has approximately 1.2 dB. It can provide a gain of approximately 25 dB in the frequency range 1850 to 1910 MHz, with the maximum noise form (at room temperature). The low noise amplifier 24 may, but need not be, an amplifier based on GaAs to allow operation at low temperatures. Such low noise amplifiers are useful, such as production number JC12-2342D produced by JCA Technologies (Camarillo, Calif.). Alternatively, low noise amplifier 24 provides similar gain levels in the low frequency range 824-849 MHZ. As such a low noise amplifier, the production number JCA01-3149 by JCA technology is useful.

delete

delete

delete

delete

delete

Equalizer 26 is shown in more detail in FIG. 2. According to one embodiment of the invention, equalizer 26 includes a circulator 30 having an input port 32, an intermediate port 34 and an output port 36. The circulator 30 may be conventionally designed, but is preferably capable of operating at low temperatures for compatibility with other components of the receive shear 10. As such a circulator 30, the same thing as the model number CT-2409N of UTE Microwave Inc (Hasbury, New Jersey) is useful. In operation, input port 32 is connected to low noise amplifier 24 to receive a filtered and amplified communication signal having group delay variation and the communication signal to intermediate port 34 for application to one port device 38. Is passed through. The one port device 38 is preferably a full pass network with a transfer function that compensates for the delay variation caused by the filter 22. The signal shown in the intermediate port 34 is processed by the plurality of resonators E-1 to E-6, reflection after the resonator E-6, and conversely, resonators E-6 to resonator E-1. Enters the one port device 38 for processing. The resonators E-1 through E-6 may include either high temperature superconducting or non high temperature superconducting components and need not be operated in low temperature environments. However, according to one embodiment of the present invention, since the similar materials or components have similar temperature response characteristics, it is preferable that the equalizer 26 and the filter 22 both have similar materials or components. That is, even though both the filter 22 and the equalizer 26 are operated at low temperatures, any temperature difference from the exact temperature at which the filter 22 and the equalizer 26 are adjusted is the filter 22 and the equalizer 26. Will affect different degrees. As a result, certain efforts to adjust the components of the receive front end 10 to achieve delay compensation may be hampered by uncontrolled ones affecting the operating temperature of the receive front end 10.

delete

delete

delete

delete

delete

delete

delete

delete

The resonators E-1 through E-6 of the one port device 38 of the equalizer 26 may be realized by a cavity resonator or a thin film high temperature superconducting technique. Thus, it should be understood that for the range in which high temperature superconducting components are used, resonators E-1 through E-6 may be implemented in thick or thin film components.

delete

If the resonators E-1 to E-6 are cavity resonators, each of the cavities is coupled through a hole disposed in the inner wall of the device housing, which will be described in more detail below with respect to FIGS. 3A and 3B. According to one embodiment of the invention, the way in which the resonators E-1 to E-6 are coupled is schematically illustrated in FIG. 2 by an opening or spacing 40 in the walls 42 separating adjacent resonators. . The opening 40 is positioned to correspond to the hole described and illustrated in FIGS. 3A and 3B.

delete

delete

The circulator 30 can be replaced by a 3-dB hybrid network, as known to those skilled in the art.

3A and 3B, the one port device 38 of the equalizer 26 is shown in more detail from two different perspectives. According to one embodiment of the invention, the resonators E-1 through E-6 are connected by a housing 50 having a pair of end walls 52 pairs, an upper wall 54 and a lower wall 56. It is implemented in each of the cavities that are defined. The housing 50 also includes a pair of plates (not shown) installed on the end walls 52, the top wall 54 and the bottom wall 56 via screws or the like. The housing 50 also includes a plurality of inner walls 58 for separating adjacent resonant cavities E-1 to E-6. The interior walls 58, which are unclear or not shown from the bi-views of FIGS. 3A and 3B, such as those defining the cavities associated with the resonators E-1, E-4 and E-5, are shown more clearly. It is desirable to resemble those shown in connection with the common cavities.

delete

delete

The housing 50 has an input / output cavity corresponding to the resonator E-1 which includes a hole (60 in FIG. 3A) for insertion of the input / output coupling mechanism, typically represented by 62 (FIG. 3B). Coupling mechanism 62 includes an antenna (not shown) for propagation (or collection) of electromagnetic waves in the cavity associated with resonator E-1. The antenna may comprise a simpler conductive loop or more complex structure that provides mechanical adjustment of the position of the conductive element in the cavity. Examples of such binding mechanisms are described in US Pat. No. 5,731,269, which is incorporated herein by reference. The coupling mechanism 62 further includes a plate 64 for mounting the antenna and cable connector 66 on the side wall 52, as shown in FIG. 3B.

delete

delete

delete

Each cavity preferably includes a resonant element (not shown), and then preferably includes a split-ring, annular resonator (eg, shown in FIGS. 7 and 8). Annular resonators may be applied in the cavity to achieve a certain degree and type of coupling, as known in the art or as shown in FIGS. 7 and 8. Each annular resonator may be installed in the lower wall 56 by a dielectric mounting mechanism. The mounting mechanism may be installed in the lower wall 56 via a screw (not shown) or the like that extends through the hole 68. The installation mechanism may be located and configured as shown in FIGS. 7 and 8. A more detailed description of a typical installation mechanism is disclosed in US Pat. No. 5,843,871, incorporated herein by reference. Other suitable dielectric installation mechanisms are shown and described in US Patent Application No. 08 / 869,399, which is hereby incorporated by reference.

delete

delete

delete

delete

Tuning of the resonators E-1 to E-6 is primarily adjusted by tuning discs (not shown) protruding into each cavity near a gap (not shown) in the annular resonator. Each tuning disk is coupled to the extended screw assembly 70 through a hole (not shown) in the top wall 54. Such mechanisms for the tuning of split-ring resonators are well known to those skilled in the art and will not be described further herein. More specifically, however, it is disclosed in the specification of US Pat. No. 5,843,871.

delete

delete

With continued reference to FIGS. 3A and 3B, resonators E-1 and E-2 are coupled through coupling holes 72 in inner wall 58. The position, size, and shape of the engagement holes 72 can be varied as will be apparent to one of ordinary skill in the art. The resonator E-2 is coupled to the resonator E-3 by the coupling hole 74, while the resonator E-3 is coupled to the resonator E-4 by the coupling hole 76, which is It may be T-shaped. The resonators E-4 and E-5 may be coupled by holes (not shown) that are similar in size and shape to the hole 78 that cross-couples the discontinuous resonators E-3 and E-6. have. Finally, resonators E-5 and E-6 are coupled by holes 80.

delete

delete

Each of the holes described above is positively coupled between each pair of resonators to establish complex zeros for delay compensation in the pass band for the communication signal. The resonators E-1 to E-6 are arranged in a zigzag shape to allow easy cross coupling between the resonators E-3 and E-6 and for optimal performance. For example, the establishment of cross coupling between resonators E-3 and E-6 is equalized to the extent that the 6-resonator design shown in FIGS. 3A and 3B performs a similar execution to the order of the 8-resonator design. Appears to improve. Zig-zag, six-step configuration also allows the strength of the bond to be minimized and then to the extent not required, non-adjacent coupling.

delete

delete

delete

In general, the shape or layout of the resonators in the housing 50 allows discontinuous resonators (eg resonators E-3 and E-6) to be close-coupled with adjacent resonators. The resonators E-1 to E-6 and the coupling holes shown in FIGS. 3A and 3B and described in connection therewith are continuous as well as discontinuous resonators to avoid undesirable coupling between non-adjacent resonators. It should also be noted that it may be designed to minimize the coupling between the resonators (eg resonators E-1 and E-2). Undesirable coupling can be particularly problematic because of the strong coupling potential when coupling resonators using components of high temperature superconductivity.

delete

delete

Adjustment of the coupling between the resonators E-1 through E-6 for the determination of the required complex zero for further tuning of the one port device 38 and delay compensation is achieved in the holes 84 of the upper wall 58. It can be achieved through the coupling screw 82 disposed. The holes 84 are preferably positioned such that each engagement screw 82 protrudes into each hole in the inner walls 58.

delete

The housing 50 of the one-port network 38 is preferably made of silver coated aluminum, but can be made of many other types of materials with low resistance. Similarly, in one embodiment of the invention the split-ring resonators may be made of low resistance metal and coated with a high temperature superconducting material. A more detailed description of the method and chemical composition of the preparation of such high temperature superconducting materials is disclosed in the specification of US Pat.

delete

delete

The one port device 38 shown in FIG. 3A includes six resonators or cavities defining six steps, while the one port device 38 has a predetermined number as required to achieve a range of equalization. The resonators eh of may have steps. In general, if about 90% of the passband requires some range of equalization (for a negligible amount of delay variation), then the number of resonators required in the one-port network 38 is equal to the filter 22 in which the delay variation occurs. It can be seen that approximately half of the number of resonators in it. If additional portions of the pass band require equalization, the number of resonators may increase. It should be noted that the assumptions above assume that the filter is a quasi-elliptic filter like each of the filters disclosed herein. If Chebyshev or other filter types are used, less equalization may be required where fewer numbers of resonators may be appropriate.

delete

delete

delete

delete

In general, however, the high temperature superconductivity and other high select filters discussed above can produce significant amounts of delay variation, especially in wideband systems such as W-CDMA. Such a case may require a large amount of delay equalization, whereby a high performance equalizer is required. As used herein, a high performance equalizer is a one-port having six or more resonators in a wireless communication system having a bandwidth of about 1% or more, and four or more resonators in a wireless communication system having a bandwidth of about 0.3% or less. Have a device. More preferably, the one port device 38 has eight or more resonators for bandwidth of about 1% or more, while six or more resonators for bandwidth of about 0.3% or less. More preferably, the one port device 38 has 10 or more resonators for bandwidth of about 1% or more, while having 8 or more resonators for bandwidth of about 0.3% or less.

delete

delete

delete

delete

Equalizer 26 may be used with a high temperature superconducting filter having a form similar to that of the one port network 38 shown in FIGS. 3A and 3B. Referring to FIG. 4, filter 22 may include sixteen resonators F-1 through F-16 implemented using thick film or thin film technology. In other cases, the resonators F-1 through F-16 are arranged in two rows as shown to facilitate continuous or discontinuous coupling. The communication signal enters filter 22 through input port 100 and resonator F-1, as schematically shown in FIG. 4, and then the signal passes through couplers 102 in a continuous manner. It is processed by resonators F-2 to F16. If the filter 22 uses thick film technology, each coupler 102 will correspond to a hole disposed in the inner wall (the same shape as described herein with respect to the equalizer 26). Details regarding the shape, location and size of the holes can be found in the above referenced US Application No. 09 / 130,274. In general, however, the couplers 102 (and the screw adjustment mechanism as described above) are designed to implement positive coupling for each pair of successive resonators.

delete

delete

delete

delete

delete

Filter 22 also includes a coupler 104 for discontinuous coupling between resonators F-7 and F-10 and between resonators F-6 and F-11. Such discontinuous coupling is designed to implement zero transmission of the filter 22 (rather than complex zero for delay compensation), and the negative coupling between the resonators F-7 and F-10 and the resonators ( Coupling coordination can be included into a room known in the art (through screws and the like) to implement positive coupling between F-6 and F-11). The strength or size of such a combination is a matter of degree to be implemented based on each case for each application of the present invention. After the communication signal propagates around (continuously) and against (discontinuously) the resonators of the filter 22, the signal is coupled to the output port 106. Both input port 100 and output port 106 may be similar to the design of input / output coupling mechanism 62 (FIG. 3) or other suitable coupling port known in the art.

delete

delete

delete

In certain applications of the present invention, the amount of delay compensation provided by equalizer 26 may be insufficient. For example, equalizer 26 may be limited to a particular order due to the difficulty of tuning in practice. In that case, it may be desirable to provide some of the residue supplied internally through the redesigned filter to some of the necessary delay compensation through the equalizer. That is, in one embodiment of the present invention, filter 22 shown in FIG. 4 is replaced by a filter, generally indicated at 108 in FIG. Filter 108 is called a magnetic equalization filter because its resonator is coupled in such a form as to provide the complex zero needed for delay equalization and compensation.

delete

delete

Referring to FIG. 5, filter 108 is similar in many respects to filter 22 of FIG. 4. For example, filter 108 may have an input / output coupling arrangement similar to input / output ports 100 and 106 and may be implemented by thick or thin film technology. In addition, the filter 108 is also preferably a high select filter, and may have 16 known devices SE-1 through SE-16 as shown, and different numbers of resonators may be suitable for different applications. It can be understood that there is. The resonators SE-1 through SE-16, although needing adjustment of the coupling strength and size as described below, are sequentially passed through the coupler 102 in a similar manner as described above with respect to FIG. Combined. The filter 108 is shown schematically in FIG. 5, with several non-continuous resonators SE-5 and SE-12; SE-6 and SE-11; and SE-7 and SE-10. It differs from the filter 22 of FIG. 4 in cross coupled alignment. Through the complex zeros set by these cross coupling alignments, all or at least some of the equalization provided by the equalizer 26 otherwise is achieved internally rather than externally.

delete

delete

delete

delete

In the embodiment shown schematically in FIG. 5 and further shown and described in connection with FIGS. 6A and 6B, the cross coupling or discontinuity between resonators SE-5 and SE-12 is positive, while resonators The coupling between SE-6 and SE-11 and the coupling between resonators SE-7 and SE-10 are both negative. For a pseudo-elliptic filter of n = 16 (as shown in FIG. 5), the (n / 2-1) / 2 resonators (i.e. resonator SE-7) and (n / 2 + 1) / 2 resonators (i.e. The coupling between resonator SE-10) is similar to the coupling between n / 2-3 resonator (i.e. resonator SE-10) and n / 2 + 2 resonator (i.e. resonator SE-12) and is typically opposite in sign. On the other hand, the coupling between the resonators SE-7 and SE-10 according to the embodiment of the present invention is similar to the coupling between the resonators SE-6 and SE-11, which is also negative.

delete

6A and 6B, one embodiment of the magnetic equalization filter 108 is shown in more detail, in particular with respect to the coupling arrangement described above. The filter 108 includes a number of structural elements identical to the cavity resonator based approach to the embodiment of the one port network 38 shown in FIGS. 3A and 3B, except that it is only two input and output ports. . In fact, the similarity of design and structure is a filter at the receive front end 10 because similar mechanisms and structures will respond similarly to temperature changes, thus minimizing the possibility of de-tuning the receive front end 10. It is preferred for proper implementation of 108. To this end, the magnetic equalization filter comprises a cavity associated with the housing 150, the end wall 152, the upper wall 154, the lower wall 156, the inner wall 158, the resonators SE-1 through SE-16. A pair of plates (not shown) to accurately define the input, input coupling mechanism (160 in FIG. 6B) for resonator SE-1, and output coupling mechanism 162 (both coupling) for resonator SE-16. Similar to mechanism 62), respective separate-ring annular resonators disposed and installed in each cavity (as shown in FIGS. 7 and 8), respective tuning disks (not shown) for each cavity, and It includes respective engagement screws (not shown) for the adjustment of each successive engagement, all of which are similar to those referenced above, and will therefore not be described further.

delete

delete

delete

Continuous engagement is also similarly established through engagement holes disposed in the inner wall 158. The coupling holes associated with the continuous coupling in the resonator rows not shown in the perspective views of FIGS. 6A and 6B preferably correspond to the size, shape and location of the coupling holes 164 associated with the rows of resonant cavities shown in practice. However, in order to increase the intensity of the sensitivity, the continuous or adjacent coupling between the resonators SE-8 and SE-9 is such that the coupling between the resonators SE-8 > It appears too strong in light of the influence on the binding of -10). As a result, the coupling holes 166 are designed to reduce the coupling between the resonators SE-8 and SE-9.

delete

delete

Looking at discontinuous coupling partially used in setting the complex zero required for equalization delay, coupling holes 170 and 172 are interposed between resonators SE-6 and SE-11 and resonators SE-7 and The coupling holes 168 lead to the necessary positive coupling between the resonators SE-5 and SE-12, while the necessary negative coupling between the SE-10) is achieved. Coupling hole 172 is also designed to be small in size to assist in efforts to reduce spurious, discontinuous coupling through resonators SE-8 and SE-9. By reducing the strength of the coupling between the resonators SE-7 and SE-10 (as well as between the resonators SE-8 and SE-9), the tuning of the magnetic equalization filter 108 is actually much more It has been found that the operation is easy and feasible.

delete

delete

7 and 8, the negative coupling between the resonators SE-6 and SE-11 and the resonators SE-7 and SE-10 is made by a coupling assembly, generally indicated at 180. The resonators SE-7 and SE-10 are shown to be implemented by a split-ring, annular resonator 181 and mounting mechanism 182. Coupling assembly 180 is preferably disposed in coupling holes 170 and 172 near resonators 181 and includes a screw 182 having a screw head 184. The screw 182 is arranged to be movable in a hole (not shown) in the upper wall 154 to position the metal rod 186 that acts as an antenna to form a cross bond. Finally, washer 188 is positioned within a seat 190 formed in top wall 154 to maintain the screw position between the adjusted positions. The screw 182 is also coupled to an elliptic dielectric insert 192 having a thread therein for receiving the screw 182. Insert 192 is installed in engagement holes 170 and 172 and thus prevents rotational movement of screw head 184 and thereby translates into vertical movement of metal rod 286. In this manner, the metal rod 186 may be positioned to form an appropriately sized bond between the cross coupled resonators. Next, cross coupling is designed to form the necessary complex zeros for delay compensation.

delete

delete

delete

delete

delete

delete

The use of magnetic equalization filter 108 (ie, replacing filter 22 with filter 108) in connection with equalizer 26 of FIG. 1 may be used in the one-port device 38 of equalizer 26. The complexity can be significantly reduced. For example, it has been found that such an embodiment can reduce the order of the one port device from six to four. Generally speaking, filter 108 will provide a reasonable amount of internal equalization, which may be sufficient to fully compensate for group delay variations in certain embodiments of the present invention. However, to reduce the complexity in system design as well as to minimize problems associated with system tuning, it is desirable to add an external equalizer to provide additional delay compensation, theoretically whether internal equalization can supply enough equalization. something to do. Indeed, such embodiments allow the system designer or technician to tune the filter 108 and equalizer 26 before the receive front end 10 is connected to the communication system. The equalizer 26 will then be fine tuned to ensure the satisfaction of the system specification for the required group delay equalization.
It should be noted that the present invention is not limited to any particular physical shape of the components at the receiving front end 10, as the above-described high selection filter and other components may or may not be integrated into a single standalone unit. Should be. Moreover, the invention is not limited to receiving shears having a single or double shape, nor is it limited to use in base stations with a certain number of sectors.
When receive front end 10 includes one or more high temperature superconducting filters, receive front end 10 may include a bypass mechanism that determines whether the high temperature superconducting filters should or should not process the input signal. The choice to bypass the high temperature superconducting filter will be addressed by a standalone integrated controller, as described in the specification, currently pending application serial number 09 / 255,896, which is hereby incorporated by reference.

delete

delete

delete

delete

delete

delete

delete

delete

In another embodiment, any one or more components of the receive shear 10 need not include components based on high temperature superconductivity. Moreover, such components may or may not be operated at low temperatures. However, it would be less burdensome to prepare and operate a system having similar components for tuning and other metrology purposes or having components designed to operate at similar temperatures.

delete

delete

The communication signal processed by the receive front end 10 is not only limited to a specific type of RF signal, but also to one type of wireless communication signal. Thus, the implementation of the present invention is well suited for, but not limited to, PCS, cellular and other wireless systems, in particular for wideband (as a result of delay variation) such as third oscillation (i.e., "3G") and W-CDMA. It is well suited for other systems with more potential).

delete

Although the receive front end 10 is particularly well suited for use in connection with wireless communication systems, and as such is discussed herein, it is common in the art that the technology of the present invention is not limited to such a usage environment. Will be evident to those who have knowledge of Conversely, receivers constructed in accordance with the techniques of the present invention will be employed in all applications having the advantage of high performance filtering and / or delay equalization provided without departing from the spirit and scope of the present invention.

delete

It is to be understood from the foregoing that the foregoing detailed description has been given for clarity of understanding only and is not intended to be an unnecessary limitation, such as obvious change by techniques in the art.

Included in the Detailed Description of the Invention

Claims (37)

In a receive front end for receiving a communication signal, A band pass filter having a high selectivity for selecting a pass band of the communication signal; An equalizer for compensating for group delay variation caused by a high selectivity ratio of the band pass filter; And A low noise amplifier protected by signals outside the pass band by the band pass filter and coupled to the equalizer to determine the noise shape of the receive front end, The bandpass filter and equalizer comprises a high temperature superconducting element, And said band pass filter, equalizer and low noise amplifier are disposed in a cryostat for operation in a low temperature environment. delete delete delete 10. The system of claim 1, wherein the communication signal is selected from the group consisting of a PCS signal and a cellular signal. 2. The system of claim 1 wherein the equalizer comprises a plurality of resonators. The method of claim 6, The equalizer further comprises a housing defining a plurality of cavities, And the plurality of resonators are disposed in the plurality of cavities, respectively. The method of claim 6, The plurality of resonators includes a pair of discontinuous resonators, And the pair of discontinuous resonators are coupled together. 10. The system of claim 8, wherein the pair of discontinuous resonators are contiguous. 2. The system of claim 1, wherein the equalizer comprises a high performance external equalizer. 2. The system of claim 1, wherein the band pass filter comprises a self equalization filter. 12. The system of claim 11, wherein said magnetic equalization filter further comprises a cryostat disposed therein. 12. The system of claim 11, wherein the magnetic equalization filter comprises a high temperature superconducting element. 14. The system of claim 13, wherein the equalizer further comprises a high temperature superconducting element. In a receive front end for receiving a communication signal, A highly selective band pass filter comprising a plurality of combining steps for selecting a pass band of the communication signal and for setting complex zeros for delay compensation within the pass band of the communication signal; And An equalizer coupled to the high selection band pass filter to provide additional delay compensation within the pass band of the communication signal, The high selection band pass filter and equalizer comprises a high temperature superconducting element, And said high selective band pass filter and equalizer is disposed in a cryostat for operation in a low temperature environment. delete delete 16. The delay equalization of claim 15, further comprising a low noise amplifier protected by the high selection band pass filter from signals outside the pass band and coupled to an equalizer to determine the noise shape of the receive front end. Wireless communication system. 19. The system of claim 18, wherein the low noise amplifier is disposed in a cryostat for operation in a low temperature environment. 16. The system of claim 15, wherein the communication signal is selected from the group consisting of a PCS signal and a cellular signal. The system of claim 15, wherein the equalizer comprises a plurality of resonators. The method of claim 21, The equalizer further comprises a housing defining a plurality of cavities, And the plurality of resonators are disposed in the plurality of cavities, respectively. The method of claim 22, The plurality of resonators includes a pair of discontinuous resonators, And the pair of discontinuous resonators are coupled to each other. The method of claim 23, And said pair of discontinuous resonators are contiguous. The method of claim 23, And said equalizer is a high performance external equalizer. In a band pass filter having a pass band, A plurality of resonators each comprising a high temperature superconducting material, The plurality of resonators includes a pair of discontinuous resonators, The pair of discontinuous resonators are combined to set a complex zero for delay compensation within the pass band, And the plurality of resonators are disposed in a cryostat for operation in a low temperature environment. 27. The system of claim 26, wherein the plurality of resonators are arranged such that the pair of discontinuous resonators are adjacent. 27. The system of claim 26, further comprising a housing defining a plurality of cavities, wherein the plurality of resonators are each disposed within the plurality of cavities. The method of claim 28, The housing includes a wall separating the pair of discontinuous resonators, And the wall comprises a hole for cross coupling the pair of discontinuous resonators. 27. The system of claim 26, wherein the band pass filter is combined with an equalizer coupled to the band pass filter to provide additional delay compensation. 31. The system of claim 30, wherein the equalizer comprises a high temperature superconducting element. 31. The system of claim 30, wherein the combination further comprises a low noise amplifier incorporating a bandpass filter in the equalizer to determine the noise shape for the combination. 33. The system of claim 32, wherein the equalizer is a high performance equalizer. 33. The system of claim 32, wherein the equalizer comprises multiple resonant devices. 35. The system of claim 34, wherein the multiple resonant device includes a housing defining a plurality of cavities. 36. The system of claim 35, wherein the multiple resonant device further comprises at least two discontinuous resonators coupled. 37. The system of claim 36, wherein the two discontinuous resonators are contiguous.

Images