RU2510980C1 - Active phase changer (versions) - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention relates to electronic engineering and specifically to microwave phase changers on semiconductor devices. The active phase changer, made on SiGe semiconductor devices and including wide-band quadrature polyphase filter, consists of series-connected sections built on RC passive circuits, and facilitating generation of two orthogonally phase-shifted quadrature signals, an analogue differential adder having Gilbert cells, an amplifier and an adder, a digital signal unit configured to control each Gilbert cell, a matching link and a converter unit for converting the differential signal into a unipolar signal; also, at the output of the quadrature polyphase filter there are four emitter followers which facilitate matching with the circuit of the analogue differential adder.

EFFECT: high reliability of the device.

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Description

The group of inventions relates to electronic equipment, namely to microwave phase shifters on semiconductor devices. The present devices can be widely used in radar systems of different frequency ranges of active phased antenna arrays.

Microwave phase shifters based on semiconductor devices are widely used in microwave technology.

Known broadband phase shifter with a controlled phase angle, containing a broadband differential quadrature filter, two proportional links with an adjustable transmission coefficient and an adder. In this case, one of the outputs of the quadrature filter is connected to the input of the first, and the other to the input of the second, providing a corresponding change in the amplitude of the quadrature components of the signal, proportional to the links whose outputs are connected to the inputs of the adder (see RF Patent No. 2303326, publ. 10.09.06) .

A disadvantage of the known device is the low reliability of the device due to the possibility of distortion of the output signal.

In addition, the prior art microwave phase shifter, which contains two transmission lines with the same wave impedances. One is for microwave input, the other is for output. It also has two field effect transistors with a Schottky barrier, the inductance of the same magnitude and capacitance of either different or the same magnitude. The source of the first field effect transistor with a Schottky barrier is connected to the transmission line at the input and to one of the ends of the first inductance, and the drain through the first capacitance is connected to the transmission line at the output and to one of the ends of the second inductance. The drain of the second field effect transistor with a Schottky barrier is connected to the other ends of both inductors and to one of the ends of the second capacitance, and the source and the other end of the second capacitance are grounded. The gates of field-effect transistors with a Schottky barrier are interconnected and connected to one source of constant control voltage (see RF Patent No. 23211106, publ. March 27, 2008).

The disadvantages of the known device is the presence of temperature instabilities of semiconductor elements and a high level of phase noise.

Also known from the prior art is a microwave phase shifter on semiconductor devices, containing two transmission lines with the same wave impedances, one for inputting a microwave signal, the other for output, a field effect transistor with a Schottky barrier, two bipolar reactive elements of either different or the same size. In this case, the drain of a field-effect transistor with a Schottky barrier is connected to one of the ends of one of the bipolar reactive elements, and its other end is connected to the output transmission line, the source of the field-effect transistor with a Schottky barrier is grounded, and a constant control voltage is applied to its gate. Two segments of the transmission line are additionally introduced into the microwave phase shifter, the first length equal to half the wavelength and less, and the second length equal to a quarter of the wavelength, while the indicated wavelength corresponds to the average frequency of the working frequency band (see RF Patent No. 2367066, publ. 09/10/2009).

The disadvantages of the known device are also low reliability, the presence of temperature instabilities of semiconductor elements and a high level of phase noise.

The objective of this group of inventions is to eliminate the above disadvantages.

The technical result consists in increasing the reliability of the device due to an increase in the stability of the output signal circuits, eliminating the presence of distortions, and also reducing the influence of time and temperature instabilities of semiconductor elements and control signals on the phase characteristics.

The technical result is ensured by the fact that the active phase shifter according to the first embodiment, made on SiGe-based semiconductor devices, includes a broadband quadrature polyphase filter, consists of series-connected sections built on RC passive circuits and allowing the formation of two quadrature signals orthogonally shifted in phase, analog a differential adder containing Hilbert cells, an amplifier and an adder, a digital signal unit configured to control azhdoy cell Hilbert block matching unit and the differential signal to unipolar converter. In addition, 4 emitter followers are provided at the output of the quadrature polyphase filter, ensuring coordination with the circuit of an analog differential adder.

The technical result is also ensured by the fact that the active phase shifter according to the second embodiment, made on GaN-based semiconductor devices, includes a broadband quadrature polyphase filter, consists of series-connected sections built on RC passive circuits, which makes it possible to form two quadrature signals orthogonally shifted in phase, an analog differential adder containing Hilbert cells, an amplifier and an adder, a digital signal unit, configured to control each Hilbert cell, the matching link and the unit of the converter of the differential signal into unipolar. In addition, 4 emitter followers are provided at the output of the quadrature polyphase filter, ensuring coordination with the adder circuit.

The essence of this group of inventions is illustrated by the following illustrations:

figure 1 - schematically shows the present device;

figure 2 - diagram of the phase shifter;

figure 3 - diagram of a polyphase filter;

4 is a diagram of a signal mixer;

5 is a diagram of the output stage of the phase shifter.

The device includes the following structural elements: broadband quadrature polyphase filter 1; analog differential adder 2; Hilbert cells 3; amplifier with adjustable gain 4; adder 5; digital signal unit for digital control 6; matching link 7; differential signal to unipolar converter block.

The present device operates as follows.

The differential input signal is split into I and Q quadrature signals using a broadband quadrature filter 1. The execution of the quadrature filter 1 can be based on various passive circuits: RC, RLC. In the present device, the polyphase filter 1 is made using RC circuits (Fig. 3). The use of several series-connected RC sections extends the signal band in which its phase remains unchanged in each of the 4 90 ° quadrants formed by filter 1. At the output of filter 1, 4 emitter repeaters are provided for matching with the circuit of an analog differential adder 2. At the outputs of repeaters ± 1 and ± Q signals are shifted by 90 °.

Differential I and Q signals are fed to an analog differential adder 2 containing an amplifier 4 with adjustable gain, a Hilbert cell 3 and an adder 5. A digital signal unit controls the gain of each Hilbert cell 3. The converted (with weight) I and Q signals are summed at the output (by amplitude), forming the synthesized phase and amplitude of the signal. Different weights in amplitude are formed by changing the gain using the digital signal unit 6.

The phase shifter operates on the principle of adding current vectors shifted by 90 degrees. The phase shift in one quadrant is controlled by changing the magnitude of the currents in each of the orthogonal vectors. In order for the output amplitude to be unchanged, the current is changed, which varies according to the law of sine, and the current, which is changed according to the law of cosine. The quadrants are switched by connecting the appropriate signal combinations from the polyphase filter 1.

The analog differential adder 2 allows, by choosing the directions of the vectors and the amplitude of the two current signals, to ensure the receipt of the resulting vector in the desired quadrant. The first stages, to which the signals are received after the polyphase filter 1, convert the voltage to current, allowing you to "linearize" the input signals and thus expand the dynamic range of the device. These cascades control two mixers (mixer circuit in Fig. 4), which are implemented (like the entire adder 2) on bipolar transistors made on the basis of GaN or SiGe. By changing the currents in 4 differential pairs of mixer transistors using a digital signal unit 6, a signal is created with the necessary phase of the resulting vector. From the output of the mixers, the signal is fed to a 3-stage differential amplifier that acts as an attenuator, the transmission coefficient of which is determined by the bias currents of the differential pairs. The values of the bias currents are set using the digital signal unit 6. The output differential signal of the attenuator is formed by two emitter repeaters.

The output stage of the phase shifter converts the differential signal into unipolar (figure 5). The output signal is formed into a unipolar one on the resistor under the influence of two signals from the emitter and collector of the output transistors. When this selection of the resistor in the matching link 7 is coordinated with the load.

This principle of implementation of the phase shifter minimizes the spectral density of phase noise (SPF) by reducing the SPF of structural elements, and also provides a minimum of nonlinear distortion of the output amplifier stage.

The use of semiconductor materials, such as SiGe, GaN, allows us to solve a number of problems in improving the operational characteristics of microwave devices: reducing phase noise, expanding the operating temperature range, increasing the permissible microwave power, expanding the frequency range, etc.

Claims (2)

1. An active phase shifter made on SiGe-based semiconductor devices and including a broadband quadrature polyphase filter consists of series-connected sections built on RC passive circuits and providing the possibility of forming two quadrature signals orthogonally phase-shifted, an analog differential adder containing Hilbert cells , amplifier and adder, digital signal unit configured to control each Hilbert cell, matching link and transform unit a differential signal receiver into a unipolar one; in addition, 4 emitter followers are provided at the output of the quadrature polyphase filter, which ensure matching with the circuit of an analog differential adder. 2. An active phase shifter made on GaN-based semiconductor devices and including a broadband quadrature polyphase filter consists of series-connected sections built on RC passive circuits and providing the possibility of generating two quadrature signals orthogonally phase-shifted, an analog differential adder containing Hilbert cells , amplifier and adder, digital signal unit configured to control each Hilbert cell, matching link and transform unit differential signal in Eqn unipolar addition, the output from the quadrature polyphase filter 4 provided emitter follower, providing harmonization with differential analog adder circuit.

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