RU161585U1 - AGREED ULTRA-HIGH FREQUENCY QUASYHARMONIC SIGNAL POWER DIVIDER - Google Patents

Abstract

Consistent power divider (SDM) 1: N microwave quasi-harmonic signals containing one input and N outputs, as well as N-1 quadrature directional couplers (BUTs) with strong coupling, made in a microstrip version, in which each BUT has a main 1-3 and secondary 2-4 channels, where the shoulders 1 and 4, as well as 2 and 3 are untied, while the NOs are connected in a chain way so that the shoulder 1 of the first HO is the input of the SDM, the shoulder 1 of the subsequent HO is connected to the shoulder 3 of the previous HO, the shoulders 4 all BUTs are connected to those agreed with path b last load Z, arms 2 of all NO and arm 3 of the last (Nl) -go NO, which are outputs of the matched divider, are connected to identical unmatched loads (LV), and for uniform power distribution, the n-th NO has a transition attenuation of 101og ( l / (- n + l + N)) dB, characterized in that N additional phase-shifting sections with low losses are additionally introduced, through which the SDM outputs are connected to the LV, and which are configured so that when the SDM is excited from its input side, the total power reflected from all LV and coming and the input signal vanishes.

Description

The utility model relates to microwave technology and can be used in active phased antenna arrays (AFAR), in particular, in transceiver modules (PPM) of AFAR as devices for dividing and summing the power of amplification stages.

The search for ways to build a matched power divider / adder (SDS) is dictated by the need to increase the power level of transistor amplifiers in the transmitting paths, increase their gain during cascading, improve matching and increase the dynamic range in the receive paths, regulate the phase of the signal in diode phase shifters, etc. New ways of matching dividers / combiners in microstrip design can form the basis for the development of previously unknown multifunctional microwave devices.

The development of SDS with coordinated output loads is one of the tasks to be solved. The problem occurs when using mismatched loads. However, here there are well-known particular solutions.

So, there are known methods for constructing matched dividers / adders based on 3 dB directional couplers (HO) and the tandem connection of 8.34 dB dB HO, in which the original signal is divided into two signals with the same amplitude and a phase difference between them of 90 degrees [1, 2]. The distribution of these methods to matched dividers with an arbitrary number of output channels is unknown.

There are also known methods of dividing and summing microwave power, requiring application for matching non-reciprocal elements (valves and circulators), which, however, complicates and increases the cost of the design [3].

In [4], for the first time, the construction of power divisors / adders 1: N for an arbitrary number of channels N, in which the chain scheme was used, was described. In it, for adding up the capacities of generators and transmitters, bridge schemes in coaxial and waveguide designs were selected as basic elements. Later in the chain scheme, for the purpose of dividing and adding the power of signal sources, the microstrip technique began to be used [3, 5, 6]. There was a need for matching at the input of dividers connected to identical uncoordinated loads.

The fact is that in the development of separation-summing devices (DCS), the loads of the divider are the inputs of microwave transistors, which often completely reflect the signal incident on them. And although this signal, partially scattered by the ballast resistors, arrives at the input of the divider weakened, it nevertheless worsens the matching of the divider with the path. Therefore, the problem arises of cascading DCSs containing such transistors.

Mismatched loads mean the inputs of transistor amplifiers, diode connections, as well as any other bipolar microwave elements or nodes that satisfy the identity criterion, i.e. when several such devices of the same type are used in the circuit, their characteristics are assumed to be the same.

Some works (for example, [5, 7]) propose measures to improve coordination, but they do not contain proposals for a radical solution to the problem.

As a prototype of an SDS, the closest divider / adder (DS) 1: N power of quasi-harmonic signals that is closest in circuitry and operation principle can be used, in which a DS containing one input and N output channels is made according to the micro-strip quadrature HO switching scheme [ 6]. The block diagram of the prototype is shown in figure 1.

The prototype contains N-1 different and well-matched quadrature tight-coupled directional couplers included in a chain pattern. HO _n with serial number n (n = 1, ... N-1 and is counted in the direction from the input / output of the divider / adder), being a four-arm device, includes the main channel 1-3, the secondary channel 2-4 and has a transition attenuation 10log (1 / (- n + 1 + N)) dB, obtained under the assumption of a uniform distribution of power at the outputs of the DS in the division mode and the absence of heat loss in HO; while shoulders 1 and 4, as well as 2 and 3 HO are untied. The chain scheme implies that the arm 3 of the main channel HO _{n is} connected to the arm 1 of the main channel HO _{n + 1} , and the working arms 2 of the secondary channels HO are connected to the same loads; when n = N-1 is also connected to the load shoulder of the main channel 3 HO _N-1. Moreover, in all cases, the untied shoulders of the 4 secondary channels are connected to the loads Z ₀ (external or internal) coordinated with the path.

In the division mode, the quasi-harmonic signal enters arm 1 HO _1, then it is divided between arms 2 and 3 and from arm 2 falls on an inconsistent load (HH), and from arm 3 it goes to arm 1 HO ₂ connected to it; no signal is received into the 4 HO ₁ arm (since the arms 1 and 4, as well as 2 and 3 of all the taps are decoupled). And so on along the whole chain.

As a result, the initial signal, due to the selected values of the transition attenuation of the couplers, enters in equal parts to all N identical to HH. Due to the farthest output N (shoulder 3 HO _N-1) from its input DS (shoulder 1 HO ₁₎ to this output signal comes from the greatest delay. The signals reflected from HH are partially absorbed by the loads Z ₀ , partially enter the input arm 1 “input / output”, worsening the coordination of the DS with the path.

In the summing mode, quasi-harmonic signals of the same power come from the side of the arms 1, ..., N, to which HH were connected in the previous case. These signals have different phases and are synchronized in such a way that when signals arrive at the "input / output" arm, the various electric paths that they travel (due to the DS chain diagram) compensate for the initial phase difference and their phases become equal to each other. The result is a lossless summation.

The disadvantages of the prototype include the lack of a constructive method for matching the DM at the input when connecting the outputs of the divider to identical HH (in particular, with a large standing wave coefficient). As a result, the transfer characteristics are distorted during cascading of separation-summing devices (DCS), which include both dividers and adders.

The technical result of the proposed utility model is to ensure matching of the DM with the path by mutually compensating for the signals reflected from the mismatched loads at the input of the 1: N divider power of the microwave power of the quasi-harmonic signal with N equal-amplitude and different-phase components.

The specified technical result is achieved due to the fact that in the coordinated power divider 1: N microwave quasi-harmonic signals containing one input and N outputs, as well as N-1 quadrature HO with strong coupling, in which each HO has a primary 1-3 and secondary 2 -4 channels, where shoulders 1 and 4, as well as 2 and 3 are decoupled, while HO is connected in a chain way so that shoulder 1 of the first HO is an SDM input, shoulder 1 of the subsequent HO is connected to shoulder 3 of the previous HO, shoulders 4 of all HO connected to ballast-matched path load am Z ₀ (external or internal), arms 2 of all HO and arm 3 of the last (N-1) th HO are SDM outputs and can be connected to identical uncoordinated loads (LV), and for uniform power distribution, the nth HO has a transition attenuation equal to 10log (1 / (- n + 1 + N)) dB (n = 1, ... N-1), N additional phase-shifting sections (FS) are introduced with low losses, through which the SDM outputs are connected to HH and which tuned so that when the SDM is excited from the side of its input, the total power of the signals reversed from all HH and received at this input was zero.

The divider can be implemented in a microstrip version, in which the HO are loop couplers, Lange couplers or tandem HO connections on two connected strip lines with a relatively weak connection between them.

FS can be segments of transmission lines of a certain length or more complex phase-shifting elements coordinated with the path, and here the phase difference between the quasiharmonic signals arriving at different output arms of the divider when it is excited from the input side is important.

The figure 2 presents a diagram of the construction of SDM 1: N power microwave quasi-harmonic signals (N is the number of outputs) of the claimed device.

SDM consists of N-1 different and strongly connected quadrature directional couplers with a tight connection, switched by a chain scheme, and N mutual FS with low losses. HO _n with serial number n (n = 1, ... N-1 and is counted in the direction from the input of the divider), being a four-arm device, includes the main channel (shoulders 1 and 3), the secondary channel (shoulders 2 and 4) and has transient attenuation of 10log (1 / (- n + 1 + N)) dB, which is obtained with a uniform distribution of power at the SDM outputs and the absence of heat loss in HO; while shoulders 1 and 4, as well as 2 and 3 HO are untied. The chain circuit implies that the arm 3 of the main channel HO _n is connected to the arm 1 of the main channel HO _{n + 1,} and the operating arms 2 HO secondary channels through phase-shifting section FS FS _n and _{n + 1} are connected to the same HH; when n = N-1, the arm 3 of the main channel HO _{N-1 is} also loaded on the LV. In all cases, the untied shoulders 4 of the secondary channels are connected to ballast loads Z ₀ (external or internal) that are compatible with the path.

The number of output channels of the divider is always one more than the number of HO: so the divider for 2 channels contains only one 3 dB HO, in the divider for 3 channels, another 4.8 dB HO is added to the 3 dB HO, in the divider 4 channel appears another 6 dB-th HO, etc. (see also [5, 6]). It can be seen that almost all HOs included in the SDM are couplers with strong coupling (with a coupling coefficient> -10 dB).

SDM works as follows. The quasi-harmonic signal enters the input / output arm (arm 1 HO ₁ ), then it is divided between arms 2 and 3 and from arm 2 through the phase-shifting section FS ₁ enters the unmatched load HH, and from arm 3 to the arm 1 connected to it HO ₂ ; no input signal is received at arm 4 HO ₁ (since arms 1 and 4, as well as 2 and 3 of all HOs are decoupled). And so on along the whole chain.

As a result, the initial signal, due to the selected values of the transition attenuation HO, runs in equal shares on the FS and then on all N identical HHs. The signals reflected from HH also in equal parts pass through the FS to the outputs of the same divider / and here the SDM works as an adder. Therefore, the summation of the signals reflected from the LV always accompanies the division mode of the original signal when the reflected signals represented by vectors in the complex plane are phased in such a way that their complex amplitudes a _n (n = 1, ... N) when the signals pass into the input / output arm »Give, when added, a closed equilateral polygon (N-gon). And this means that there is no total reflected signal at the input, since its amplitude is zero. Physically, this is due to the fact that the power of the reflected signals from the NN scattered by ballasting Z ₀ and the divisor input (shoulder "input / output") is not received.

Obviously, when N = 3, the equilateral triangle shown in FIG. Indeed, for this case, α is calculated by the formula:

,

,

where φ _{n + 1} -φ _n - difference in phase shifts waves coming from the shoulder "input / output" mutual SDM shoulders n + 1 and n, respectively (n = 1,2; N = 3). For N> 3, formula (1) describes a regular polygon, which, however, can be deformed. Such a deformation means that formula (1) becomes unfair and there is an ambiguity in the choice of phase shifts of the signals reflected from the LV. The ambiguity of the choice of FS allows, in turn, the possibility of using additional criteria (compact location, broadband, etc.) when designing a divider that is consistent with the path.

The foregoing is illustrated in FIG. 3 b, c, d, which show examples of summation, implemented by selecting the phase difference between adjacent sections of FS _{n + 1} and FS _n . Thus, FIG. 3b shows a particular case of a square (N = 4) of the amplitudes of the reflected signals with α = π / 2, and FIG. Figures 3c and 3d show general cases when conditions (1) for N = 4 are not satisfied (α ≠ π / 2), and the square, remaining a closed polygon, is deformed into a rhombus.

SDM can be used as an adder (for example, when building DCS [5, 6]). In it, quasi-harmonic signals of the same power arrive at the DM from the shoulders, to which in the previous case the LVs were connected. The signals are phased in such a way that when they enter the input / output arm, the phases of the signals become equal to each other. Then the complex amplitudes of these signals a _n (n = 1, ..., N) will be represented by collinear vectors of the same length, and when added will be located on a straight line, giving the total vector a = a ₁ + ... + a _{n of} maximum length ( Fig. 4). It should be noted here that entering the matched load Z ₀ equals zero power. Indeed, in the mode under consideration, all signals arriving at each HO consist of signals arriving at arms 2 and 3 of HO. They are phased and, having the amplitudes identical in absolute value, in the output arms 1 and 4 HO add up in phase and out of phase, respectively.

Examples.

1. Figure 5 shows a diagram of a 1: 3 divider for antidirectional HO with electromagnetic coupling between channels (BUTs of the Lange type, placed on a polycrust substrate 2 mm thick, ε = 9.8). The open end of the 50 Ohm microstrip line or its short circuit was used as HH. 50 Ohm microstrip lines of fixed length L1, L2, L3 functioned as phase-shifting sections. In fairness, it should be noted that with quadrature HO, the lengths L1, L2, L3 are calculated on a calculator.

2. Figure 6 shows the DCS circuit in which the divider described above (Fig. 5) was used as a power divider (DM) and a power combiner (SM). Amplifiers (U) are switched on between the DM and the SM, as shown in the figure, or some other four-terminal devices with identical characteristics.

The circuits were modeled on a computer using the Microwave Office suite. Figure 7 shows the frequency characteristics of the standing wave coefficient (SWR) at the input of the divider (Fig. 5) for four cases: the two upper curves are calculated at L1 = L2 = L3 = 10 mm when HH is the open end of the line (curve 1) or short closure (curve 2); the two lower curves correspond to the case when the amplitudes of the signals reflected from HH were folded into a triangle (see Fig. 3a) and obtained at L1 = 20.9 mm; L2 = 15 mm; L3 = 8 mm; and HH is the open end (curve 3) or short circuit (curve 4). Lange taps in all cases had the following dimensions: HO ₁ - length 20.9 mm, strip width 0.2 mm, gap between strips 0.4 mm; HO ₂ - length 20.2 mm, strip width 0.2 mm, the gap between the strips 0.18 mm For the circuit of figure 6, identical segments of microstrip lines with a varying length and a variable wave impedance ZL (7 Ohm <ZL <100 Ohm) were chosen as identical quadripoles. Calculations carried out in the same frequency range as above showed good matching of the DCS for input and output.

Thus, the introduction of the well-known 1: N divider, made according to the chain scheme, consistent with the path of mutual FS with low losses, made it possible to obtain a simple and effective input-compatible divider

the power of quasi-harmonic signals 1: N for any N> 2, and the technical implementation of SDM in the microstrip version allows obtaining compact multi-channel separation-summing devices.

Literature

1 Microwave electronic devices: textbook for radio engineering specialties of universities / G.I. Veselov, E.N. Egorov, Yu.N. Alekhine et al .; Ed. G.I. Veselova. - M .: Higher. School, 1988. - 280 p. 2 Petrov G.V., Tolstoy A.I. Linear balanced microwave amplifiers. - M .: Radio and communications, 1983. - 176 p.

3 Kaganov V.I. Microwave semiconductor transmitters. - M: Radio and communications, 1981. - 400 p.

4 Katushkina V.M., Model Z.I. Bridge methods for adding power to any number of VHF generators and transmitters. - Telecommunications, 1959, No. 7, p. 17.

5 Gorbachev A.P. Synthesis of microwave devices on coupled transmission lines. - Novosibirsk: NSTU Publishing House, 2010 .-- 414 p.

6 Phased Antenna Design: A Textbook for High Schools / Edited by D.I. Voskresensky. - M .: Radio engineering, 2012 .-- 744 p.

7 RF patent №2123231 RF, IPC6 H03F 3/60, H03H 11/02. Microwave separation and summing device / A.P. Gorbachev. Application No. 96121200/09 of 10.30.1996; published December 10, 1998, Bulten No. 34. - 6 p.

Claims (1)

Consistent power divider (SDM) 1: N microwave quasi-harmonic signals containing one input and N outputs, as well as N-1 quadrature directional couplers (BUTs) with strong coupling, made in a microstrip version, in which each BUT has a main 1-3 and secondary 2-4 channels, where the shoulders 1 and 4, as well as 2 and 3 are untied, while the NOs are connected in a chain way so that shoulder 1 of the first HO is the input of the SDM, shoulder 1 of the subsequent HO is connected to shoulder 3 of the previous HO, shoulders 4 all BUTs are connected to the llastnym loads Z _0, all BUT shoulders 2 and 3, the latter arm (Nl) -th BUT, which are the outputs of coherent divider are connected to the identical mismatched loads (NN) and for even distribution of n-th power BUT has transient attenuation equal to 101og (l / (- n + l + N)) dB, characterized in that N additional phase-shifting sections with low losses are additionally introduced, through which the SDM outputs are connected to the LV, and which are configured so that when the SDM is excited from the input side total power reflected from all LV and received this signal input went to zero.

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