Ultra-wideband GaAs amplitude-phase control transceiver front-end chip

Abstract

The application discloses an ultra-wideband GaAs amplitude-phase control transceiver front-end chip, which is applied to the field of phased array radars, and aims at the fact that high-low pass type phase shifters adopted in existing transceiver front-end chips are only applicable to low-frequency phase shift units, and are limited by the problem of filter order; the application proposes a novel phase shift structure based on a magnetic coupling all-pass network and an active complementary dual-mode amplification circuit, the structure can realize a great expansion of available frequency on the premise of ensuring phase shift precision, and a 180-degree phase shift network based on an active structure can effectively provide transmission gain, reduce the number of used link amplifiers, further reduce the noise coefficient of a receiving link and assist in improving the power characteristics of a transmitting link. The application of the technology helps to realize good phase shift precision, input and output return loss and lower phase shift error of the chip in an ultra-wideband range of 2-18GHz.

Description

Technical Field

[0001] This invention belongs to the field of phased array radar, and specifically relates to a transceiver front-end technology. Background Technology

[0002] With the continuous development of militarization and the evolution of combat thinking, modern warfare has evolved from traditional combat methods to a war model centered on electronic warfare and information warfare. Integrated electronic warfare systems have become one of the key weapons in modern warfare. To meet the diverse operational needs of radar countermeasures, radio communication countermeasures, and optoelectronic countermeasures, a complete electronic countermeasures platform often integrates separate electronic warfare systems with ultra-wideband bandwidth and different functions. Such complex requirements objectively lead to defects such as excessive platform size, low integration, and poor consistency, which greatly limits the platform's mobile combat performance. The transceiver front-end is a key component of electronic countermeasures phased array radar, and its performance determines key technical indicators such as beam rate scanning accuracy, transmit power, and receive sensitivity of the phased array system. At the same time, the improvement of the overall performance of electronic countermeasures systems requires the corresponding transceiver front-end to develop towards low cost, low power consumption, light weight, and miniaturization. Due to the unique ultra-wideband characteristics of electronic countermeasures systems, existing transceiver front-end multi-functional chips often adopt a segmented form. This implementation method not only increases costs but also reduces the overall system integration and the response speed of switching between different functions. Currently, multi-functional chips in phased array radars are mainly made of GaAs. Although GaAs has superior carrier mobility, gallium arsenide substrates have poor thermal performance and high processing costs. Therefore, the processing technology of III-V semiconductor chips such as GaAs and SiC cannot meet the cost reduction requirements of applications. Thus, low-cost, high-performance silicon-based technology will become the preferred technology for miniaturization, low power consumption, and high reliability of military phased array radars. Therefore, developing a high-performance, ultra-wideband, low-cost silicon-based transceiver front-end chip with complete independent intellectual property rights is of great practical significance for the construction of my country's integrated electronic warfare platform.

[0003] like Figure 1As shown, the design of the high-pass / low-pass network phase shifter uses a switching linear phase shifter network as a reference. Phase shifting is achieved by introducing impedance networks in different branches. This design also requires single-pole double-throw (SPDT) switches. Taking a T-type filter circuit as an example, when the signal is conducted through the SPDT circuit and the T-type high-pass filter circuit, the output signal leads the input signal. Switching the SPDT switch activates the T-type low-pass filter network, causing a phase lag. Therefore, a phase difference exists between the two states. By controlling the switching device to change the conducting branch of the electrical signal, phase shifting can be achieved. Due to the presence of the high-pass and low-pass filters, the above circuit structure has two different resonant frequencies. The leading phase of the high-pass filter circuit is negatively correlated with frequency; the leading phase tends to decrease as the frequency increases. Conversely, the lagging phase of the low-pass filter circuit increases with frequency. The two filter circuits exhibit complementary phase changes at the same frequency range. The series reactance and shunt susceptance of a high-pass filter are inversely proportional to the frequency change, while the series reactance and shunt susceptance of a low-pass filter are directly proportional to the frequency change. Therefore, the phase shifter can achieve matching over a relatively wide frequency range. At the same time, if the frequency increases, the phase lead angle of the high-pass filter decreases while the phase lag angle of the low-pass filter increases, which can be compensated to keep the phase difference between the two states at a certain value over a relatively wide frequency band.

[0004] However, high-pass and low-pass phase shifters are only suitable for use between low-frequency phase shifting units and are limited by the filter order. Therefore, they are not suitable for phase shifters with bandwidths of 2-18 GHz. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes an ultra-wideband GaAs amplitude-phase control transceiver front-end chip. Based on a novel phase-shifting structure of a magnetically coupled all-pass network and an active complementary dual-mode amplifier circuit, this structure can significantly expand the usable frequency range while maintaining phase-shifting accuracy. The 180° phase-shifting network based on the active structure effectively provides transmission gain, reduces the number of link amplifiers, further reduces the noise figure of the receiving link, and helps improve the power characteristics of the transmitting link. This technology helps the chip achieve good phase-shifting accuracy, low input / output return loss, and low phase-shifting error within the 2-18 GHz ultra-wideband range.

[0006] The technical solution adopted in this invention is as follows: an ultra-wideband GaAs amplitude and phase control transceiver front-end chip, comprising: a 5.625° phase shifter, an 11.25° phase shifter, a 22.5° phase shifter, a 45° phase shifter, a 90° phase shifter, a 180° phase shifter, a distributed amplifier, and a switch;

[0007] The input terminal of the 180° phase shifter is connected to a switch, and the output terminal of the 180° phase shifter is connected to the input terminal of the 45° phase shifter.

[0008] The output of the 45° phase shifter is connected to the input of the distributed amplifier;

[0009] The output of the distributed amplifier is connected to the input of the 5.625° phase shifter, the output of the 5.625° phase shifter is connected to the input of the 11.25° phase shifter, the output of the 11.25° phase shifter is connected to the input of the 22.5° phase shifter, the output of the 22.5° phase shifter is connected to the input of the 90° phase shifter, and the output of the 90° phase shifter is connected to a switch.

[0010] The 45° phase shifter and 90° phase shifter adopt a switch-selective magnetically coupled full-pass network topology;

[0011] The 5.625° phase shifter, 11.25° phase shifter, and 22.5° phase shifter adopt a series capacitor-type magnetically coupled all-through network topology.

[0012] The 180° phase shifter uses an active circuit topology.

[0013] The beneficial effects of this invention are as follows: This invention proposes a novel phase-shifting structure based on a magnetically coupled all-pass network and an active complementary dual-mode amplifier circuit. This structure can significantly expand the usable frequency range while ensuring phase-shifting accuracy. The 180° phase-shifting network based on the active structure can effectively provide transmission gain, reduce the number of link amplifiers, further reduce the noise figure of the receiving link, and help improve the power characteristics of the transmitting link. This technology helps to achieve good phase-shifting accuracy, low input / output return loss, and low phase-shifting error in the chip within the ultra-wideband range of 2-18 GHz. Attached Figure Description

[0014] Figure 1 For existing high-pass / low-pass schematics;

[0015] Among them, (a) is schematic example one, and (b) is schematic example two;

[0016] Figure 2 This is a structural diagram of the magnetically coupled all-pass network phase-shifting unit based on series capacitors according to the present invention;

[0017] Figure 3 This invention relates to a phase-shifting topology based on a magnetically coupled all-pass network.

[0018] Among them, (a) is a series capacitor type, and (b) is a switch selection type;

[0019] Figure 4 This is a structural diagram of the variable capacitor of the present invention;

[0020] Figure 5 The equivalent circuit diagram provided for this invention;

[0021] Among them, (a) the equivalent circuit of the magnetically coupled all-pass network, (b) the odd-mode equivalent circuit, and (c) the even-mode equivalent circuit;

[0022] Figure 6 This is a structural diagram of an active complementary dual-mode amplifier circuit.

[0023] Figure 7 This is a schematic diagram of an active complementary dual-mode amplifier circuit.

[0024] Figure 8 This is the full phase-shifted state of the ultra-wideband phase shifter;

[0025] Figure 9 This represents the ground-state insertion loss of the ultra-wideband phase shifter.

[0026] Figure 10 For the input and output standing waves of an ultra-wideband phase shifter;

[0027] Wherein, (a) is the input standing wave diagram and (b) is the output standing wave diagram. Detailed Implementation

[0028] To facilitate understanding of the technical content of this invention by those skilled in the art, the following description, in conjunction with the accompanying drawings, further illustrates the invention.

[0029] In the transceiver chip of this invention, a 5.625° phase shifter, an 11.25° phase shifter, and a 22.5° phase shifter are cascaded. The input of the cascaded phase shifter is connected to the output of a distributed amplifier, and the output of the cascaded phase shifter is connected to the input of a 90° phase shifter. In the 2-18GHz ultra-wideband GaAs amplitude and phase control transceiver front-end chip, the input of a 45° phase shifter is connected to the output of a 180° phase shifter, and the output of the 45° phase shifter is connected to the input of a distributed amplifier. In the 2-18GHz ultra-wideband GaAs amplitude and phase control transceiver front-end chip, the input of a 90° phase shifter is connected to the input of the cascaded 5.625°, 11.25°, and 22.5° phase shifters, and the output of the 90° phase shifter is connected to a switch. In the 2-18GHz ultra-wideband GaAs amplitude and phase control transceiver front-end chip, the input of a 180° phase shifter is connected to a switch, and the output is connected to the input of a 45° phase shifter. The phase shifter achieves excellent impedance matching and ultra-wideband high-precision phase shifting functionality in a 2-18GHz ultra-wideband GaAs amplitude and phase control transceiver front-end chip.

[0030] In the broadband transceiver multifunction chip designed in this invention, the phase shifter plays a crucial role. The performance of this component directly affects the phase shifting accuracy. The transceiver front-end chip of this invention covers 160% of the relative bandwidth, which traditional phase shifters cannot meet. Conventional solutions often adopt a segmented structure to achieve phase shifting and time-division reconfiguration at different frequencies. However, the segmented structure significantly increases the system complexity, reduces the system integration, and the switching speed also affects the overall response time of the electronic warfare system.

[0031] Therefore, this invention creatively proposes a novel phase-shifting structure based on a magnetically coupled all-pass network and an active complementary dual-mode amplifier circuit. The magnetically coupled all-pass network structure can significantly expand the usable frequency range while ensuring phase-shifting accuracy, while the active 180° phase-shifting network can effectively provide transmission gain, reduce the number of link amplifiers, further reduce the noise figure of the receiving link, and help improve the power characteristics of the transmitting link. This technology helps the chip achieve good phase-shifting accuracy, low input / output return loss, and low phase-shifting error in the ultra-wideband range of 2-18 GHz.

[0032] The phase-shifting principle of a magnetically coupled all-pass network phase-shifting unit based on a series capacitor can be understood similarly to a high / low-pass structure. The signal flows in from the left port; part of the signal flows to the output via Cs (equivalent to a series capacitor, high-pass network, phase leading), and the other part of the signal reaches the output via a coupling inductor and a parallel capacitor (equivalent to a low-pass T-type network with a series inductor and a parallel capacitor, phase lagging). The signal flows between the leading and lagging aspects of the two branches, achieving phase shifting. Furthermore, it boasts high phase-shifting bandwidth and accuracy. A magnetically coupled all-pass network phase-shifting unit based on a series capacitor is shown below. Figure 2 As shown.

[0033] The dual-channel inverting output phase shifter with active gain compensation circuitry has the following topology: Figure 6 As shown, this design primarily targets the maximum phase shift unit of 180°, employing an active circuit topology. This allows for ultra-wideband phase shifting while also providing some gain to compensate for the insertion loss of the entire phase shifter. After the RF signal is introduced at the input (assuming the input signal is 0°), it first passes through a common-source amplifier to output a signal with a 180° phase. Simultaneously, it passes through a source follower to output a signal in phase with the input signal, also at 0°. These two output signals are then each inverted by a common-source amplifier. Finally, two series-parallel single-pole double-throw switches are used to achieve the final output. Based on this, a 180° phase difference exists between the signals on the two paths. This structure achieves ultra-wideband, high-precision phase shifting while also providing high flatness gain and output power.

[0034] First, the phase-shifting principle of magnetically coupled all-pass networks will be introduced.

[0035] Phase shifters based on magnetically coupled all-pass networks mainly have two topologies: switch-selective and series-capacitor type, such as... Figure 3 As shown. Figure 3 (b) is a switch-selective magnetically coupled all-pass network topology, where the selection of the two all-pass networks by a single-pole double-throw switch characterizes the ground state and phase-shifted state of the phase-shifting circuit. This structure typically achieves a large phase shift, but introduces significant losses and occupies a large circuit area. This structure is used in the 45° and 90° phase shifters of this invention. In this paragraph, "larger" refers to a phase shift greater than or equal to 45°.

[0036] Figure 3 (a) is a series capacitor-type magnetically coupled all-through network topology. This structure is typically used to obtain smaller phase shifts. Its advantages include lower losses and a smaller circuit area. Therefore, this structure is used in the 5.625°, 11.25°, and 22.5° phase shifters of this invention. The variable capacitor is implemented by a combination of a switching transistor and a fixed capacitor, such as... Figure 4 As shown, using V G The equivalent capacitance of the entire circuit is changed by controlling the on and off states of the switching transistor, thereby achieving the state transition between the ground state and the phase-shifted state of the phase-shifting circuit. "Smaller" refers to a phase shift of less than or equal to 22.5°.

[0037] Figure 3 In the switch-selective magnetically coupled all-pass network topology shown in (b), the key parameter for determining the bandwidth, the magnetic coupling coefficient k, can take values ​​in the range of -1 to 1. The absolute value of k determines the coupling strength, and the polarity determines the directionality of the signal through the coupling coil. Its equivalent circuit is as follows: Figure 5 As shown in (a). The mutual inductance coefficient M can be calculated using the magnetic coupling coefficient k and the inductance value L of the coupled coil, as shown in formula (1):

[0038] M=kL (1)

[0039] For ease of analysis, the equivalent circuit is divided into left-right symmetrical circuits with the intermediate axis as the center line, namely, odd-mode equivalent circuits and even-mode equivalent circuits, as follows: Figure 5 (b) and Figure 5 As shown in (c). The odd-mode impedance and even-mode admittance can be obtained from equations (2) and (3):

[0040]

[0041]

[0042] C p Right now Figure 3 The parallel capacitor C in p0 Cs Right now Figure 3 The series capacitor Cs0 in the middle;

[0043] The odd-even mode reflection coefficients of the circuit can be obtained by equivalent inductive reactance and capacitive reactance, as shown in formulas (4) and (5):

[0044]

[0045]

[0046] Where Z0 represents the characteristic impedance and Y0 represents the characteristic admittance.

[0047] Therefore, the S-parameters of the magnetically coupled all-pass network can be extracted using formulas (6) and (7):

[0048]

[0049]

[0050] Among them, S 11 S represents return loss. 21 Indicates insertion loss;

[0051] According to formulas (4) and (5), under certain conditions, S 11 The value of the parameter is always 0 at any frequency, and the values ​​of the parameter are as shown in formulas (8) and (9):

[0052] b s =(1+k)x (8)

[0053] b p =(1-k)x (9)

[0054] Substituting formulas (8) and (9) into (6) and (7), we can obtain S. 21 The phase expression is:

[0055]

[0056] And at this time |S 21 |=1.

[0057] In the 180° phase-shift circuit design, an active circuit topology was adopted, which provides a certain gain while achieving broadband phase shift, resulting in a more reasonable allocation of link parameters and a significant reduction in the overall power consumption of the chip. For example... Figure 6As shown, the input single-ended signal is converted from single-ended to differential via an active balun, then passed through a high-gain differential amplifier to improve the amplitude and phase balance of the differential signal and compensate for gain. Finally, a single-pole double-throw switch selects the output of the two differential signals, thus achieving a 180° phase shift. This structure provides high flatness gain and power output while achieving ultra-wideband high-precision phase shift.

[0058] The principle of an active complementary dual-mode amplifier circuit: The radio frequency signal is introduced at the input terminal (assuming the input signal is 0°), and passes through a common-source amplifier and a common-gate amplifier respectively, outputting signals with phases of 180° and 0°. These signals are then amplified and inverted by the common-source amplifier, and finally, a single-pole double-throw switch is used to select the output. The schematic diagram is shown below. Figure 7 As shown:

[0059] This invention effectively extends the bandwidth and compensates for the decrease in high-frequency gain, while also improving circuit stability. The final result of the ultra-wideband phase shifter is as follows: Figure 8 , 9 As shown in Figure 10.

[0060] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the scope of the claims of the invention.

Claims

1. An ultra-wideband GaAs amplitude and phase control transceiver front-end chip, characterized in that, include: 5.625° phase shifter, 11.25° phase shifter, 22.5° phase shifter, 45° phase shifter, 90° phase shifter, 180° phase shifter, distributed amplifier, switch; The input terminal of the 180° phase shifter is connected to a switch, and the output terminal of the 180° phase shifter is connected to the input terminal of the 45° phase shifter. The output of the 45° phase shifter is connected to the input of the distributed amplifier; The output of the distributed amplifier is connected to the input of the 5.625° phase shifter, the output of the 5.625° phase shifter is connected to the input of the 11.25° phase shifter, the output of the 11.25° phase shifter is connected to the input of the 22.5° phase shifter, the output of the 22.5° phase shifter is connected to the input of the 90° phase shifter, and the output of the 90° phase shifter is connected to a switch. The 45° phase shifter and 90° phase shifter adopt a switch-selective magnetically coupled full-pass network topology; The phase shifter, 11.25° phase shifter, and 22.5° phase shifter adopt a series capacitor-type magnetically coupled full-pass network topology; The 180° phase shifter uses an active circuit topology. The switch-selective magnetically coupled all-pass network topology includes a first single-pole double-throw switch, a second single-pole double-throw switch, a first all-pass network, and a second all-pass network. Specifically, the selection of the two all-pass networks by the single-pole double-throw switch is used to characterize the ground state and phase-shifted state of the phase-shifting circuit.

2. The ultra-wideband GaAs amplitude and phase control transceiver front-end chip according to claim 1, characterized in that, A series-capacitor-type magnetically coupled full-pass network topology includes a first variable capacitor, a second variable capacitor, a first inductor, and a second inductor. A first terminal of the first inductor is connected to a first terminal of the first variable capacitor, a second terminal of the first variable capacitor is connected to a first terminal of the second inductor, a second terminal of the first inductor is connected to a first terminal of the second variable capacitor, a second terminal of the second variable capacitor is grounded, and a second terminal of the second inductor is connected to a second terminal of the second variable capacitor. The first terminal of the first inductor serves as the input terminal of the series-capacitor-type magnetically coupled full-pass network topology, and the first terminal of the second inductor serves as the output terminal of the series-capacitor-type magnetically coupled full-pass network topology. The variable capacitor is implemented by a combination of a switching transistor and a fixed capacitor. By controlling the switching transistor to turn on and off, the equivalent capacitance of the entire circuit is changed, thereby realizing the state transition between the ground state and the phase-shifting state of the phase-shifting circuit.

3. The ultra-wideband GaAs amplitude and phase control transceiver front-end chip according to claim 1, characterized in that, The active circuit topology is as follows: the input single-ended signal is converted from single-ended to differential through an active balun, and then the differential signal amplitude and phase balance and gain compensation are improved and achieved through a high-gain differential amplifier. Finally, the two differential signals are selected and output through a single-pole double-throw switch, thereby achieving 180° phase shift.

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