Network analyzer of multichannel spread spectrum module and measuring method thereof

Abstract

The invention relates to a network analyzer of multi-channel spread spectrum modules and a measurement method thereof. The network analyzer comprises a network analyzer and a plurality of multi-channel spread spectrum modules, the network analyzer is provided with a source port and is used for sending a fundamental frequency signal f0 to the spread spectrum module; each multi-channel spread spectrum module is provided with a reference channel, a transmitting channel and a measuring channel; the reference channel comprises a first frequency multiplier and a first frequency mixer; the transmitting channel comprises a second frequency multiplier, an isolator and a coupler; the measurement channel comprises a third frequency multiplier and a second frequency mixer. According to the invention, the plurality of change-over switches are correspondingly connected with the plurality of multi-channel spread spectrum modules, simultaneous or time-sharing measurement of multiple channels is realized, the measurement efficiency and flexibility are improved, power amplification, amplitude stabilization and power division are carried out on radio frequency signals and local oscillator signals through the multi-channel spread spectrum modules, the coupler is responsible for separating measurement signals from reference signals, and the measurement accuracy is improved. And the highest frequency of the spread spectrum system can reach 1THz.

Description

Technical Field

[0001] The invention relates to the field of radio frequency microwaves, and in particular to a network analyzer of a multi-channel spectrum spreading module and a measurement method thereof. Background Art

[0002] Vector network analyzer (VNA) is a highly precise electromagnetic energy test instrument. It is an important core measurement instrument in the field of microwave and millimeter wave measurement. Its core structure consists of signal source, power divider, switch, receiver, and coupler. With the further development and application of millimeter wave technology in recent years, vector network analyzers have undergone a transformation from manual point frequency measurement to fully automatic network analyzers, and then to high-speed and highly integrated programmable network analyzers, accompanied by a comprehensive improvement in the test accuracy, measurement speed, test bandwidth, and upper frequency limit of vector network analyzers.

[0003] The Chinese invention patent named "Spectrum Spreading Module and On-Wafer Test System" and patent number CN202011520529.8 provides a spectrum spreading module and an on-wafer test system, including: a microwave switch, which sends the excitation signal to the first or second frequency multiplier; an amplifier, which amplifies the second frequency multiplier signal; a directional coupler, which transmits the signal to a dual directional coupler; a dual directional coupler, which directly outputs a part of the output signal of the directional coupler, and couples the other part of the output as a reference signal, and couples the feedback signal of the test piece through another coupling branch; an attenuator, which attenuates the first frequency multiplier signal to obtain linear parameters, and directly outputs the second frequency multiplier signal to obtain nonlinear parameters; a first mixer, which generates a reference intermediate frequency signal; and a second mixer, which generates a test intermediate frequency signal. The present invention uses a microwave switch switching method to obtain small signals and large signals, and is set up at the same time on a high and low temperature probe station, so as to complete the linear and nonlinear parameter amplitude and phase error calibration and continuous frequency scanning test of the millimeter wave terahertz amplifier chip in a high and low temperature environment.

[0004] In the prior art, the on-wafer test system is only equipped with one spread spectrum module, and its test flexibility, accuracy, reliability, scalability and upgradeability are all limited. It is difficult for the on-wafer test system to cover a wide frequency range and comprehensively test different S parameters. In addition, the calibration difficulty is increased, the risk of single-point failure is high, and the maintenance cost is high. At the same time, it is difficult to adapt to the upgrade of future test needs and the update of technological development. Summary of the invention

[0005] The technical solution of the present invention to solve the above technical problem is as follows: a network analyzer with a multi-channel spectrum spreading module, comprising a network analyzer and a plurality of multi-channel spectrum spreading modules; A network analyzer having a source port for sending a baseband signal f0 to the spread spectrum module; The multi-channel spectrum spreading modules all have a reference channel, a transmission channel and a measurement channel; The reference channel includes a first frequency multiplier and a first frequency mixer; The transmitting channel includes a second frequency multiplier, an isolator and a coupler; The measurement channel includes a third frequency multiplier and a second frequency mixer; The switching switches correspond to the number of the plurality of multi-channel spectrum spreading modules and are used to respectively control the connection status between the network analyzer and the plurality of multi-channel spectrum spreading modules.

[0006] Preferably, the multi-channel spectrum spreading module further comprises a power divider for power dividing the input baseband signal f0 and outputting the power-divided baseband signal f0 to the reference channel and the measurement channel.

[0007] Preferably, the transmitting channel receives the baseband signal f0 generated by the network analyzer, generates a high-frequency signal f0*n through a second frequency multiplier, and outputs it through a coupler port after passing through an isolator; The coupler has a through end and a coupling end, the through end is used to output a radio frequency signal for mixing to the first mixer, and the coupling end is used to output a radio frequency signal for mixing to the second mixer.

[0008] Preferably, the reference channel receives the baseband signal f0 output by the power divider, generates a high-frequency signal f0*n through a first frequency multiplier, and serves as a local oscillator driving signal for the first mixer; The first mixer is used to mix the local oscillator driving signal with the radio frequency signal output from the through-port of the coupler to output an intermediate frequency signal to the network analyzer.

[0009] Preferably, the measurement channel is used to receive the RF signal f0 through a third frequency multiplier and amplify it to obtain a high-frequency signal f0*n. The high-frequency signal f0*n and the coupled end output signal of the coupler are mixed through a second mixer to output a stable RF measurement signal and input it into the network analyzer.

[0010] The present invention also discloses a method for measuring a multi-channel spread spectrum module, which specifically comprises the following steps: S1: Generate baseband signal f0 through network analyzer; S2: Input the baseband signal f0 to the transmission channel of the spectrum spreading module, generate a high-frequency signal f0*n through the frequency multiplier and transmit it; S3: input another baseband signal f0 into the power divider of the spectrum spreading module to split it into two signals, and then generate high-frequency signals f0*n as the local oscillator signal of the reference channel and the local oscillator signal of the measurement channel through frequency multiplication and amplification respectively; S4: In the reference channel, the RF signal is mixed with the local oscillator signal to obtain the intermediate frequency signal, which is then input to the network analyzer; S5: In the measurement channel, the reflected signal of the high-frequency device under test is received, mixed with the signal coupled through the coupler and the local oscillator signal, and the intermediate frequency signal is obtained and input into the network analyzer; S6: The network analyzer receives and processes the intermediate frequency signals from the reference channel and the measurement channel, and calculates and displays the S parameters of the high frequency device; S7: By controlling the on and off of the switching switch, the spectrum spreading module is switched to achieve multi-channel simultaneous or time-sharing measurement.

[0011] The beneficial effects of the present invention are as follows: the present invention connects multiple multi-channel spread spectrum modules through multiple switching switches to achieve simultaneous or time-sharing measurement of multiple channels, thereby improving measurement efficiency and flexibility, and performs power amplification, amplitude stabilization, and power division on radio frequency signals and local oscillator signals through the multi-channel spread spectrum modules, and the coupler is responsible for separating the measurement signal from the reference signal, so that the maximum frequency of the spread spectrum system can reach 1THz. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A schematic diagram of the structure of a network analyzer with a multi-channel spectrum spread module according to the present invention; Figure 2 The present invention is a schematic diagram of the working connection structure of a network analyzer with a multi-channel spectrum spreading module.

[0013] In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. Power divider; 2. First frequency multiplier; 3. Second frequency multiplier; 4. Third frequency multiplier; 5. Isolator; 6. First mixer; 7. Second mixer; 8. Coupler. DETAILED DESCRIPTION

[0014] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0015] like Figure 1 , Figure 2 As shown, a network analyzer with a multi-channel spread spectrum module comprises a network analyzer and a plurality of multi-channel spread spectrum modules; A network analyzer having a source port for sending a baseband signal f0 to the spread spectrum module; The multi-channel spectrum spreading modules all have a reference channel, a transmission channel and a measurement channel; The reference channel includes a first frequency multiplier 2 and a first mixer 6; The transmitting channel includes a second frequency multiplier 3, an isolator 5 and a coupler 8; The measurement channel includes a third frequency multiplier 4 and a second frequency mixer 7; The switching switches correspond to the number of the plurality of multi-channel spectrum spreading modules and are used to respectively control the connection status between the network analyzer and the plurality of multi-channel spectrum spreading modules.

[0016] In an embodiment, the multi-channel spectrum spreading module further includes a power divider 1 for power dividing an input baseband signal f0 and outputting the power-divided baseband signal f0 to a reference channel and a measurement channel.

[0017] In the embodiment, the transmitting channel is used to receive the baseband signal f0 generated by the network analyzer, generate a high-frequency signal f0*n through the second frequency multiplier 3, and output it through the port of the coupler 8 after passing through the isolator 5; The coupler 8 has a through end and a coupling end. The through end is used to output a radio frequency signal for mixing to the first mixer 6 , and the coupling end is used to output a radio frequency signal for mixing to the second mixer 7 .

[0018] Specifically, the isolator 5 is used to prevent the baseband signal from being reflected back to the second frequency multiplier 3 and burning the device.

[0019] In the embodiment, the reference channel is used to receive the baseband signal f0 output by the power divider 1, and generate a high-frequency signal f0*n through the first frequency multiplier 2 as a local oscillator driving signal of the first mixer 6; The first mixer 6 is used to mix the local oscillator driving signal with the radio frequency signal output from the through end of the coupler 8 to output an intermediate frequency signal to the network analyzer.

[0020] In an embodiment, the measurement channel is used to receive the RF signal f0 through the third frequency multiplier 4, and amplify it to obtain a high-frequency signal f0*n. The high-frequency signal f0*n and the coupled end output signal of the coupler 8 are mixed through the second mixer 7 to output a stable RF measurement signal and input it into the network analyzer.

[0021] Specifically, the source port of the network analyzer gives the spread spectrum module a baseband signal f0, one baseband signal enters the transmitting channel, is amplified by the second frequency multiplier 3, and is output through coupling as the local oscillator signals of the first mixer 6 and the second mixer 7 respectively. The other baseband signal is divided into two by the power divider 1, one of which is used as the local oscillator signal f0 of the reference channel, and the signal f0*n is obtained by the first frequency multiplier 2. This signal is used as the local oscillator driving signal of the first mixer 6. The RF signal output from the through-end of the coupler 8 is mixed with the local oscillator signal f0*n, and the intermediate frequency signal is output and input into the network analyzer.

[0022] The other signal divided by the power divider 1 enters the measurement channel, is amplified by the third frequency multiplier 4, and is mixed with the signal output from the coupling end of the coupler 8 to be used as the measurement signal.

[0023] The present invention also discloses a method for measuring a multi-channel spread spectrum module, which specifically comprises the following steps: S1: Generate baseband signal f0 through network analyzer; S2: Input the baseband signal f0 to the transmission channel of the spectrum spreading module, generate a high-frequency signal f0*n through the frequency multiplier and transmit it; S3: input another baseband signal f0 to the power divider 1 of the spectrum spreading module to split it into two signals, and then generate high-frequency signals f0*n as the local oscillator signal of the reference channel and the local oscillator signal of the measurement channel through frequency multiplication amplification respectively; S4: In the reference channel, the RF signal is mixed with the local oscillator signal to obtain the intermediate frequency signal, which is then input to the network analyzer; S5: In the measurement channel, the reflected signal of the high-frequency device under test is received, mixed with the signal coupled by the coupler 8 and the local oscillator signal, and the intermediate frequency signal is obtained and input into the network analyzer; S6: The network analyzer receives and processes the intermediate frequency signals from the reference channel and the measurement channel, and calculates and displays the S parameters of the high frequency device; S7: By controlling the on and off of the switching switch, the spectrum spreading module is switched to achieve multi-channel simultaneous or time-sharing measurement.

[0024] Specifically, the measurement method of the multi-channel spread spectrum module generates a baseband signal through a network analyzer, outputs a high-frequency signal excitation after amplification by a frequency multiplier, and simultaneously uses a power divider 1 to divide another baseband signal into two local oscillator signals as reference and measurement channels. In the reference channel and the measurement channel, the radio frequency signal is mixed with the local oscillator signal to obtain an intermediate frequency signal. The network analyzer receives and processes these signals to calculate and display the S parameters of the high-frequency device.

[0025] In the process of measuring S parameters, by controlling the switching switch, simultaneous or time-sharing measurement of multiple channels is achieved, thereby improving the measurement efficiency and flexibility. The switching switch is a single-pole multi-throw switch, which is used in multiple spread spectrum modules.

[0026] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A network analyzer with a multi-channel spread spectrum module, characterized in that: Includes network analyzer and multiple multi-channel spread spectrum modules; A network analyzer having a source port for sending a baseband signal f0 to the spread spectrum module; The multi-channel spectrum spreading modules all have a reference channel, a transmission channel and a measurement channel; The reference channel comprises a first frequency multiplier (2) and a first frequency mixer (6); The transmission channel comprises a second frequency multiplier (3), an isolator (5) and a coupler (8); The measurement channel comprises a third frequency multiplier (4) and a second frequency mixer (7); The switching switches correspond to the number of the plurality of multi-channel spectrum spreading modules and are used to respectively control the connection status between the network analyzer and the plurality of multi-channel spectrum spreading modules.

2. The network analyzer of the multi-channel spectrum spreading module according to claim 1, characterized in that: The multi-channel spectrum spreading module further comprises a power divider (1) for power dividing an input baseband signal f0, and outputting the power-divided baseband signal f0 to a reference channel and a measurement channel.

3. The network analyzer of the multi-channel spectrum spreading module according to claim 2, characterized in that: The transmitting channel is used to receive the baseband signal f0 generated by the network analyzer, generate a high-frequency signal f0*n through the second frequency multiplier (3), and output it through the port of the coupler (8) after passing through the isolator (5); The coupler (8) has a through end and a coupling end, the through end being used to output a radio frequency signal for mixing to the first mixer (6), and the coupling end being used to output a radio frequency signal for mixing to the second mixer (7).

4. The network analyzer with a multi-channel spectrum spreading module according to claim 2, characterized in that: The reference channel is used to receive the baseband signal f0 output by the power divider (1), and to generate a high-frequency signal f0*n through the first frequency multiplier (2) as a local oscillator driving signal of the first mixer (6); The first mixer (6) is used to mix the local oscillator drive signal with the radio frequency signal output from the through end of the coupler (8) to output an intermediate frequency signal to the network analyzer.

5. The network analyzer with a multi-channel spectrum spreading module according to claim 2, characterized in that: The measurement channel is used to receive the radio frequency signal f0 through the third frequency multiplier (4), and amplify it to obtain a high frequency signal f0*n. The high frequency signal f0*n and the coupled end output signal of the coupler (8) are mixed through the second mixer (7) to output a stable radio frequency measurement signal, which is input into the network analyzer.

6. The network analyzer of the multi-channel spectrum spreading module according to any one of claims 3 to 5, characterized in that: Said n is a positive integer.

7. A method for measuring a network analyzer of a multi-channel spread spectrum module, comprising the network analyzer of the multi-channel spread spectrum module according to any one of claims 1 to 6, characterized in that: The specific steps include: S1: Generate baseband signal f0 through network analyzer; S2: Input the baseband signal f0 to the transmission channel of the spectrum spreading module, generate a high-frequency signal f0*n through the frequency multiplier and transmit it; S3: input another baseband signal f0 into the power divider (1) of the spectrum spreading module to split it into two signals, and then generate high-frequency signals f0*n as the local oscillator signal of the reference channel and the local oscillator signal of the measurement channel through frequency multiplication and amplification respectively; S4: In the reference channel, the RF signal is mixed with the local oscillator signal to obtain the intermediate frequency signal, which is then input to the network analyzer; S5: In the measurement channel, receiving the reflected signal of the high-frequency device under test, mixing it with the signal coupled by the coupler (8) and the local oscillator signal, obtaining an intermediate frequency signal and inputting it into the network analyzer; S6: The network analyzer receives and processes the intermediate frequency signals from the reference channel and the measurement channel, and calculates and displays the S parameters of the high frequency device; S7: Controls the on and off of the switching switch, switches the spread spectrum module, and realizes multi-channel simultaneous or time-sharing measurement.

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