Ultra-wideband phase shifter chip applied to phased array transceiver

Abstract

The invention belongs to the technical field of integrated circuits, and particularly relates to a phase shifter applied to a wireless communication system. The circuit structure of the phase shifter comprises an orthogonal signal generator, a variable gain amplifier and a synthesis network. An input signal generates a differential quadrature differential signal through the quadrature signal generator, the differential quadrature differential signal is amplified, weighted and subjected to polarity adjustment through the variable gain amplifier, and the differential quadrature differential signal is synthesized at the output end through the synthesis network. According to the phase shifter applied to the wireless communication system, amplitude and phase mismatch is reduced due to recombination of IQ signals of the coupler, impedance matching is carried out on an output port of the orthogonal signal generator and an input port of the variable gain amplifier, broadband high-precision IQ signals can be generated, and broadband phase shifting is achieved; and the transistor array unit of the IQ signal can be independently controlled and is easy to expand, so that enough states can be used for selecting a required phase shift state, and high-precision and high-resolution phase shift can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated circuits, and particularly relates to a phase shifter. Background Art

[0002] A phase shifter is a circuit or device that can adjust the phase of an electromagnetic wave signal and has wide applications in modern electronic communication systems, including but not limited to wireless communication systems, phased array radars, measurement and sensing.

[0003] Among several types of phase shifters such as switch type, reflection type, and vector synthesis type, the vector synthesis type phase shifter has the advantages of wide bandwidth, high precision, low insertion loss, and high resolution. The vector synthesis type phase shifter is a phase shifter that realizes phase control by using the principle of vector decomposition and synthesis. It decomposes the input signal into orthogonal I and Q components, adjusts the amplitude and phase respectively, and then synthesizes the adjusted components for output. By adjusting the amplitude and sign of the I and Q components, an output signal with any phase can be obtained.

[0004] With the continuous development of wireless communication systems, especially in applications of 5G, 6G, and higher frequency bands, the demand for ultra-wideband signal processing is increasing. Therefore, there is an expectation for a phase shifter that can provide stable phase control in the ultra-wideband range and has advantages such as high precision, low insertion loss, low power consumption, and high linearity. Summary of the Invention

[0005] The object of the present invention is an ultra-wideband high-precision phase shifter applied to a phased array transceiver. The ultra-wideband high-precision phase shifter applied to a phased array transceiver proposed by the present invention has a circuit structure including: an orthogonal signal generator, an inter-stage matching network, a variable gain amplifier, and an output synthesis network. The differential input signal generates a differential orthogonal differential signal through a transformer-based orthogonal signal generator, is amplified, weighted, and polarity-adjusted by the variable gain amplifier, and the adjusted orthogonal signal is synthesized into an output signal through the synthesis network.

[0006] In the present invention, the orthogonal signal generator includes a first-stage coupler and several stages of polyphase networks, and each stage of polyphase network is composed of two couplers. The differential input signal generates differential orthogonal signals (I+, I-, Q+, Q-) through the coupler, and then the IQ signals are combined. The signal output from the through end of the I-path coupler is connected in phase with the signal output from the coupled end of the Q-path coupler, and the signal output from the coupled end of the I-path coupler is connected in antiphase with the signal output from the through end of the Q-path coupler, generating IQ signals with smaller amplitude-phase errors.

[0007] In the present invention, the variable gain amplifier includes a differential common-source amplifier. The signal is input from the gate of the common-source transistor. The drain of the common-source transistor is connected in parallel with N groups of cross-connected transistor array units. The width-to-length ratio of the unit transistors increases in binary, and the gates of the transistors are controlled by DC 0V or 1.2V. The drain ends of the transistor array units are connected in parallel and output after being combined by a synthesis network.

[0008] In the phased array designed by the present invention, due to the recombining of the IQ signals of the coupler, the amplitude and phase mismatches are reduced, and broadband high-precision IQ signals can be generated. Moreover, since the transistor array units of the IQ signals can be independently controlled and are easy to expand, there are enough states available for selecting the required phase shift states, and high-precision and high-resolution phase shift can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 FIG. is a schematic structural diagram of the ultra-wideband high-precision phase shifter of the present invention.

[0010] Figure 2 FIG. is a schematic circuit diagram of the quadrature signal generator.

[0011] Figure 3 FIG. is a schematic diagram of the coupler model in the quadrature signal generator.

[0012] Figure 4 FIG. is a schematic circuit diagram of the variable gain amplifier. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described in more detail below with reference to the drawings. In the respective drawings, the same elements are denoted by like reference numerals. For the sake of clarity, the various parts in the drawings are not drawn to scale. In addition, some well-known parts may not be shown in the figures.

[0014] Many specific details of the present invention, such as the structure, materials, dimensions, processing techniques and technologies of the devices, are described below in order to understand the present invention more clearly. However, as those skilled in the art can understand, the present invention can be implemented without these specific details.

[0015] Figure 1 FIG. shows a schematic structural diagram of the ultra-wideband high-precision phase shifter of the present invention.

[0016] As Figure 1As shown in the figure, the ultra-wideband high-precision phase shifter 100 in the present invention includes a quadrature signal generator 101, an inter-stage matching network 102, a variable gain amplifier 103, and a synthesis network 104. The input signal generates differential quadrature signals I+, I-, Q+, and Q- after passing through the quadrature signal generator 101. The IQ signals are respectively used as the inputs of two groups of variable gain amplifiers 103 after passing through the inter-stage matching network 102. The outputs of the two groups of variable gain amplifiers 103 obtain differential output signals Vout+ and Vout- after passing through the synthesis network 104.

[0017] Figure 2 The schematic diagram of the quadrature signal generator circuit is shown.

[0018] As Figure 2 shown in the figure, the quadrature signal generator 200 includes a first-stage quadrature coupler 201 and a polyphase filter composed of the quadrature coupler 201. The input signals IN+ and IN- generate primary IQ signals I0+I0- and Q0+Q0- through the coupler. The initial IQ signals are respectively input to the input ends of a quadrature coupler. The output signals of the two quadrature couplers are recombined, that is, the through-end output signal of the I-path coupler is connected in phase with the coupled-end output signal of the Q-path coupler, and the coupled-end output signal of the I-path coupler is connected in antiphase with the through-end output signal of the Q-path coupler to generate the final IQ output signal.

[0019] Figure 3 It is the schematic diagram of the coupler model in the quadrature signal generator.

[0020] As Figure 3 shown in the figure, the differential coupler is composed of two groups of couplers. By adjusting the coupling coefficient of the coupler > 0.707, the signals at the coupled end and the through end can be orthogonal in phase and equal in amplitude at two frequency points, and orthogonal signals with low phase mismatch and amplitude mismatch can be generated in a wider frequency band. The two couplers make the area of the quadrature signal generator more compact through layout folding, and at the same time, the transmission lines used for connection participate in the inter-stage impedance matching.

[0021] Figure 4 The schematic diagram of the variable gain amplifier circuit is shown.

[0022] As Figure 4 shown in the figure, the variable gain amplifier includes a common-source amplifier composed of M5 and M6 and a transistor array unit composed of M1_x, M2_x, M3_x, and M4_x. Among them, the gates of M1_x and M4_x are biased by the same control signal, and the gates of M3_x and M3_x are biased by the inverted control signal. L1 and L2 are peaking inductors used to reduce the high-frequency insertion loss caused by parasitic capacitance. The sources and drains of all array units are connected together, and the aspect ratios of the unit transistors are 1, 2, 4... 2 NThe input signal is amplified by M5 and M6 and then input to the source of the transistor array unit, and is output at its drain end after being weighted and polarity-adjusted by the array unit.

[0023] In this document, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a series of elements (such as a process, method, article or device) including the recited elements not only includes those elements, but also includes other elements not expressly listed. Without further limitation, an element limited by the statement "comprising a..." does not exclude the existence of additional identical elements other than the recited element.

[0024] In the present invention, the embodiments do not describe all the details in detail, nor limit the invention to the specific embodiments described. According to the above description, many changes can be made. These embodiments are selected and specifically described in this specification in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and its modifications based on the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A phase shifter applied to a phased array, characterized in that, The circuit structure includes: an orthogonal signal generator, an inter-stage matching network, a variable gain amplifier, and an output combining network. The differential input signal generates a differential quadrature signal through a transformer-based orthogonal signal generator, and is amplified, weighted, and polarity-adjusted by the variable gain amplifier. The adjusted orthogonal signal is combined into an output signal through the combining network.

2. The phase shifter applied to the phased array according to claim 1, characterized in that, The orthogonal signal generator includes a first-stage coupler and several stages of polyphase networks, and each stage of polyphase network is composed of two couplers. The differential input signal generates a differential quadrature signal (I+I-Q+Q-) through the coupler, and then the differential quadrature signal is combined through the coupler. The signal output from the through-end of the I-path coupler is connected in phase with the signal output from the coupled-end of the Q-path coupler, and the signal output from the coupled-end of the I-path coupler is connected in antiphase with the signal output from the through-end of the Q-path coupler to generate the final IQ output signal.

3. The phase shifter applied to the phased array according to claim 2, characterized in that, The variable gain amplifier contains a differential common-source amplifier. The signal is input from the gate of the common-source transistor. The drain of the common-source transistor is connected in parallel with N groups of cross-connected transistor array units. The width-to-length ratio of the unit transistors increases in binary, and the transistor gates are controlled by DC 0V or 1.2V. The drain ends of the transistor array units are connected in parallel, and the drain-end signals are combined through the combining network and then output.

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