RU2692480C1 - High-resolution microwave phase-shifting unit - Google Patents

Abstract

FIELD: electronic equipment.SUBSTANCE: invention relates to electronic engineering, specifically to microwave phase-shifting unit on semiconductor devices. Phase-shifting unit are widely used in communication equipment, radar and measurement equipment. Main signal is selected substantially larger (approximately by 10–12 dB) of the auxiliary signal. Auxiliary signal, passing through the digital attenuator, is summed with the main signal on the adder. As a result of vector addition of signals at the output of the adder, a signal is obtained, which is phase-shifted relative to the main signal by a value depending on the level of the auxiliary signal. By controlling the digital attenuator, the required small shifts can be obtained. By selecting digit capacity of digital attenuator and pitch of change of attenuation, it is possible to select required range and minimum discretion of phase change. According to another version of disclosed invention, disclosed in the proposed phase-shifting unit are two multi-bit phase-shifting units, wherein the second phase-shifting unit is connected in series with the first phase shifter. First phase-shifting unit provides phase control in range of 180 to 5.625 degrees with discreteness of 5.625 degrees, and second, providing installation of required phase with discrepancies in tenths of degrees, and to ensure monotony of phase adjustment into phase-shifting unit digital driver is introduced, which provides conversion of required phase setting into cascade control signals based on phase errors of discrepancies. Input signal supplied to the two-channel divider is divided into 2 streams: the main signal and the auxiliary one with phase shift between them of 90 degrees, which enables to realize minimum discrepancies in phase shifts of less than 5.625 to 0.088 degrees (2.812, 1.406; 0.703; 0.352; 0.176, and 0.088).EFFECT: facilitating implementation of minimum discrepancies of phase shifts.2 cl, 10 dwg

Description

The invention relates to electronic engineering, in particular to microwave phase shifters on semiconductor devices. Phase shifters (EFs) are widely used in communications equipment, radiolocation and measurement technology.

Phase shifters are with continuous and discrete phase changes, while the latter are a cascade connection of several, at least, from two to 5-6 digits containing calibrated segments of transmission lines providing the specified phase shift. The connection and disconnection of the transmission line segments in each discharge is carried out by electronic switches, which use semiconductor diodes or transistors.

Microwave phase shifters are characterized by:

- the maximum and minimum magnitude of the microwave phase change (phase step, phase discrete);

- working width;

- the magnitude of the loss of the microwave signal;

- monotony of change of phases at their change;

- the accuracy of setting the specified phase value;

- parameters of control signals.

Usually, for example, in a six-digit phase shifter, the values of discharges are 180, 90, 45, 22.5, 11.25, and 5.623 degrees. The inclusion of different sections can provide a phase change in the range from 360 to 0 degrees with a minimum step of 5.625 degrees.

However, for practical tasks, for example, in measuring equipment or in high-resolution radar systems, phase changes may be required in increments of the order of 0.1 degrees.

The one shown in FIG. 1 discrete loop-shaped microwave diode phase shifter (RF patent №2231175 C2; IPC: H01P 1/185; 20.06.2006), consisting of microstrip sections, equipped with a diode connecting the loop ends and an associated matching element. The switched matching element in the form of a short-loop loop connected to the middle of the loop through the diode is made in sections with a large sampling, and in sections with a small sampling - as a line in the connection section through the diode of the loop ends with an impedance exceeding 1.5-2 times the wave resistance resistance of the main line and loop.

The one shown in FIG. 2 microwave frequency shifter (RF patent №2316086 C1; IPC: H01P 1/185; 27.01.2008), containing 2 transmission lines with the same wave impedances, one for the microwave signal input, the other for the output, two Schottky barrier field-effect transistors and a segment of the transmission line with a length equal to half the wavelength in the transmission line. The source of the first field-effect transistor with a Schottky barrier is connected to the transmission line at the input, and the drain to the transmission line at the output and to one of the ends of the transmission line segment. The other end of the transmission line segment is connected to the transmission line at the input. The drain of the second field-effect transistor with a Schottky barrier is connected to a segment of the transmission line at a distance equal to a quarter of the wavelength in the transmission line from either its end, its source is grounded. The gates of field-effect transistors with a Schottky barrier are interconnected and connected to one source of constant control voltage.

The one shown in FIG. 3 microwave phase shifter (RF patent №2401489 C1; IPC: H01P 1/18; 10.10.2010), containing 2 transmission lines with the same wave impedances, one for the microwave signal input, the other for the output, two Schottky barrier field-effect transistors, inductance and capacitance of the same size, additionally entered a segment of the transmission line with a length equal to one eighth of the wavelength at the middle frequency of the working frequency band, with a characteristic impedance equal to the characteristic impedance of the transmission line at the input, with one end of one with the transmission line at the input and with one end of the first capacitance, the other end of the said transmission line segment is connected to the transmission line at the output and one end of the second capacitance, the other end of each capacitance is connected to the drain of each Schottky barrier field effect transistor and also the end of each inductance, the value of which is determined from the mathematical expression depending on the average frequency of the working frequency band and the output capacitance of the transistors.

The one shown in FIG. 4 Microwave phase shifter based on semiconductor circuit (RF patent №2379798 C1; IPC: Н01Р 1/18; 01.20.2010). The microwave phase shifter based on a semiconductor circuit contains two parallel channels, the inputs and outputs of which, respectively, are connected to the input and output microstrip lines, the first channel containing the first field-effect transistor with the Schottky gate, the first phase-shifting element in the form of a microstrip line and the second field-effect transistor with a Schottky gate, the second channel is a successively connected third field-effect transistor with a Schottky gate, the second phase-shifting element and the fourth field-effect transistor p with the gate Schottky, and the gates of all transistors are connected by resistors for supplying control voltage, according to the invention, the second phase-shifting element is replaceable and located outside the functional surface of the semiconductor circuit, and the width of the gate of each field-effect transistor is equal to the width of microstrip lines.

In addition, the second phase-shifting element can be made in the form of a microstrip line.

In addition, the second phase-shifting element can be made in the form of LC circuits on lumped elements.

The implementation of the second replaceable phase-shifting element in the form of a microstrip line or LC-circuits on lumped elements allows you to implement any phase discrete multi-bit phase shifter of the selected frequency range.

The one shown in FIG. 5 pass-through discrete semiconductor microwave phase shifter (RF patent №2639992 C1; IPC: H01P 1/185; 25.12.2017), matched with the characteristic impedance of the main transmission line, made on the basis of the connection of the transmission line segments and control elements, mainly diodes. The input and output of the phase shifter circuit of the phase shifter are connected via a control element. The phase shifter circuit of the phase shifter contains a low-pass filter in the form of a series connection of three (in the case of a discrete greater than 90 degrees) or two (in the case of a discrete less than or equal to 90 degrees) transmission line segments, to the points (points) of which the plugs are connected , and their free ends (the ends of the central conductors) are connected via microwave to the body (screen) through control elements, the geometrical parameters of the mentioned segments and loops are chosen from the condition of providing quarter-wave electric lengths s each transmission line from the input (output) of the phase-shifting circuit to the nearest point of connection with the body, and the wave impedances of these segments exceed the wave impedance.

The one shown in FIG. 6 wideband multi-bit discrete microwave phase shifter (RF patent №172993 U1; IPC: Н01Р 1/185; 03.08.2017). A device consisting of N series-connected discharges, which include a phase-shifting element (FSE) and a support element (OE) containing the first and second pin diodes OE, the first and second capacitors OE, OT inductance, OE additionally introduced the second and third inductance OE, and in FSE, containing the first and second pin diodes of FSE, first and second capacitors of FSE and inductance of FSE, the second inductance of FSE and the third capacitor of FSE with the appropriate connections are added.

As can be seen, the well-known multi-digit microwave pass-through phase shifters have two transmission lines with the same wave impedances, between which phase-shifting sections are located (in the form of an LC circuit, semiconductor diodes, or simply segments of transmission lines) in the required number with discrete values from 180 to 5.625 degrees. The reduction of discretes in such a design is almost impossible due to the small phase-shifting segment of 2.812 degrees, etc. degrees commensurate with the influence of other elements of the scheme.

The actual problem is the creation of a phase-shifting device with discrete phase increments from units to 0.1 degrees.

Closest to the essence of the claimed invention is presented in FIG. 7 technical solution of a semiconductor integrated circuit of a multi-bit phase shifter (Elesin V.V., Nazarova G.N., Usachev N.A., Chukov G.V., Sotskov D.I. “Construction of monolithic integrated circuits of multi-digit microwave phase shifters with improved accuracy characteristics ", Journal" News of universities. ELECTRONICS ", No. 5, Zelenograd, MIET, 2012, p. 31-38) for an active microwave antenna array. The original in this work is the implementation of the microwave phase shifter using SiGe-BiCMOP technology on a single chip using the amplitude adjustment of the orthogonal components of the generated signal. The idea of adjusting the amplitude of one of the signal components was used in the proposed application when implementing a phase shifter according to microstrip technology, which makes it possible to consider this a prototype of the invention. A variant of multi-bit PV in monolithic design with amplitude-controlled amplifiers using the principle of addition of orthogonal vectors (Fig. 7a) is proposed. FIG. 7b is a block diagram of the vector PV. This scheme allows you to rotate the phase of the output signal only within 90 degrees. To rotate the phase within 360 degrees, it is necessary to include in series 4 schemes shown in FIG. 7b, which complicates the device and is a disadvantage of this technical solution.

In comparison with the technical solution shown in FIG. 7, the proposed technical solution has the advantage of using the widely used microstrip technology and its relative cheapness, which allows the developer to implement an embodiment suitable for his particular task.

The technical result of the invention is the ability to ensure the implementation of the minimum sampling phase shifts less than 5,625 to 0,088 degrees (2,812; 1,406; 0,703; 0,352; 0,176 and 0,088) degrees.

The technical result is achieved by the fact that the input signal 1 (Fig. 8) is fed to a two-channel divider 2 where it is divided into 2 streams: the main signal Aos 3 and auxiliary Avs 4 with a phase shift between them of 90 degrees. In this case, the main signal Aos 3 is chosen more than the signal Avs 4 by 13.1 dB, so that at zero attenuation of the digital attenuator 5, to provide a phase shift of the output signal of 2.812 degrees. Signal 4 via Digital Attenuator 5, the output signal of which is 6, is fed to one input of adder 7, and to the second input of which the main signal 3 is fed. by an amount dependent on the level of the auxiliary signal of the Avs 6. By controlling the digital attenuator 5 on the input 9 you can get the required small shifts (Fig. 9). By choosing the bit width of the digital converter and the attenuation step, one can choose the required range and the minimum discrete phase change as it is done in the technical solution shown in FIG. 7

This effect of controlling the phase of a signal is explained by the fact that, as is known from mathematics, a linear combination of several sinusoidal quantities with the same frequency is a sinusoidal quantity with the same frequency. In our case, we have after divider 2 two sinusoidal signals with the same frequency, but shifted in phase by 90 ° relative to each other. After adder 7, a linear combination of two sinusoidal values is formed:

For our case, ϕ ₁ = 0; ϕ ₂ = 90 °; ϕ - phase shift after summation of signals. Then the formula (1) takes the form:

From formula (2) it follows that:

tg (β) = A _sun / A _os ;

Thus, to obtain a phase shift of 5.625 degrees, the amplitude ratio of the summed signals should be 0.09849. And to obtain a phase shift of 2.812 degrees, the amplitude ratio of the summed signals must be 0.04912.

The proposed version of the phase shifter 10 to provide small changes in the level of the output signal 8 during phase reorganization is preferably suitable for implementing small phase shifts, approximately in the range from 10-15 degrees to hundredths.

The proposed microwave phase shifter can provide the necessary value of the phase shift in the required range from 2.83 to 0.088 degrees with the number of phase values from 6 to 16, depending on the step of changing the attenuation of the TsA (3 or 1 dB).

The obtained values of phase shifts at decay step in TsA in 1 dB are equal to:

According to another embodiment of the claimed invention, the technical result is achieved in that the proposed phase shifter uses two multi-digit phase shifters, the second phase shifter being connected in series with the first one. The first phase shifter 11 (FIG. 10) provides phase control in the range from 180 to 5.625 degrees with discretes 5.625 degrees, and the second phase shifter 13 provides switchable fixed phase values in the range from 2.82 to 0.087 degrees.

To ensure the monotony of the characteristics of the phase adjustment with small discretes, it is necessary that the errors in the settings of the phases of the previous discretes do not exceed half of the subsequent lower digits. Practically, this requirement for the number of digits of more than 6 is impossible without the use of measures of digital correction of control errors.

To do this, the HIGH-DISTRIBUTED UHF PHASE TRUCKER must include a digital driver 15, which provides transcoding of the required phase shift values into codes that take into account the non-ideality of real samplers of phase shifters 11 and 13. ROM 15 (Fig. 10) can be used as such a driver, in which the transcoding of signals can be used the required phase shift 16 in the codes of signals 17, taking into account the phase errors of discrete. The necessary codes must be formed during the manufacture and calibration of the high-digit phase shifter individually for each sample.

The offered PV can be made both in microstrip, and in monolithic execution.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically represents a discrete loop-shaped diode microwave phase shifter. 1-loop; 2-sections of the transmission line; 3, 7, 10-diode; 4 and 5 - input and output sections of the transmission line; 11 short-circuited cable.

FIG. 2 shows the microwave phase shifter. 1, 2 - lines of input / output of the microwave signal; 3, 4 - field-effect transistors with a Schottky barrier; 5 - line segment transmission; 6 - a source of control voltage.

FIG. 3 schematically shows a microwave phase shifter. L1, L2 - inductance; C1, C2 - capacity; T1, T2 - transistors; Z0 is the characteristic impedance.

FIG. 4 is a schematic representation of a microwave phase shifter based on a semiconductor circuit. 2, 3 - input and output microstrip line; 4, 6, 7, 9 - field-effect transistors with a Schottky gate; 5, 8 - phase-shifting elements; 10 - resistors.

FIG. 5 shows a pass-through discrete semiconductor microwave phase shifter. 1 - the main transmission line; 2, 2 '- segments of the transmission line; 3 - loop; D ₁ and D ₂ - control elements (diodes).

FIG. 6 shows a broadband multi-bit discrete microwave phase shifter. 1 - phase-shifting element (FSE); 2 - supporting element (OE); 3, 4, 14 - the first, second and third capacitors of the FSE; 5, 13 - the first and second inductances of FSE; 6, 7 - the first and second pin diodes of the FSE; 8, 9 - the first and second pin diodes OE; 10, 11 - the first and second capacitors OE; 12, 15, 16 - the first, second and third inductance OE.

FIG. 7 explains the principle of addition of orthogonal vectors (a) and the block diagram of the vector PV (b).

FIG. 8 shows a microwave phase shifter circuit.

FIG. 9 shows phase shifts.

FIG. 10 is a diagram of the microwave phase shifter.

Thus, the proposed high-resolution microwave phase shifter differs from the previous versions in that in order to ensure a 360 degree change with a small discrete, it uses a phase shifter section with small discrete values ranging from units to hundredths of a degree by changing the level of the orthogonal component and sections phase shifter with increments from 180 to 5,623 degrees with phase-shifting elements. This allows you to provide the entire range of phase change in the range of 360-0.1 degrees.

Claims (2)

1. The microwave phase shifter containing an asymmetrical quadrature power divider, a digital multi-bit attenuator and a two-channel adder, characterized in that the output signal of the divider with an increased level of the reference signal is fed to one input of the adder, and the second quadrature output signal of the divider with a reduced signal level is fed through a digital attenuator to the second input of the adder, which provides a controlled phase shift of the output signal of the phase shifter relative to the input when the digital transmission coefficient changes attenuator. 2. High-frequency microwave phase shifter with minimization of phase change discretes, characterized in that it consists of two series-connected phase shifters, the first of which provides a coarse phase change in the range of 180-5.625 degrees with a resolution of 5.625 degrees, and the second, according to claim 1, providing setting the required phase with samples in tenths of a degree, and to ensure the monotony of phase reorganization, a digital driver is introduced into the phase shifter, which ensures the conversion of the required phase setting into the cascade control signals taking into account the phase errors of the samples.

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