US 2022/0103402 A1Published application

Signal analysis apparatus and signal analysis method

AssigneeAnritsu Corporation

InventorsShinichi ITO, Shunsuke HINOOKA, Yoshitaka KIHARA, Mamoru IWAMOTO

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Abstract

A signal analysis apparatus includes a frequency conversion unit 10 that includes a first local oscillator 11 which outputs a first local oscillation signal SLO1 of a frequency fLO1, a first mixer 12 which generates a first spurious signal of a frequency fSP1, a first BPF 13 of a passed center frequency f0, a second local oscillator 14 which outputs a second local oscillation signal SLO2 of a frequency fLO2, and a second BPF 16 of a passed bandwidth W, and that performs frequency conversion of a measured signal SRF of a frequency fRF (center frequency fc), in which the frequency fLO1 and the frequency fLO2 are shifted using a frequency shift amount Δf that does not establish a relationship of −W/2≤|fSP1−f0±fIF2−Δf|−fIF2≤+W/2.

Claims4

Dependent claims

A signal analysis apparatus that analyzes a measured signal (SRF) having a frequency component fRF, the signal analysis apparatus comprising:

a frequency setting unit that decides a first intermediate frequency fIF1, a frequency fLO1 of a first local oscillation signal, and a frequency fLO2 of a second local oscillation signal in accordance with a center frequency fc of the measured signal;
a first local oscillator that outputs the first local oscillation signal (SLO1);
a first mixer that generates a first intermediate frequency signal (SIF1) of the first intermediate frequency fIF1 by performing frequency mixing of the measured signal with the first local oscillation signal and generates a first spurious signal (SSP1) including a second harmonic component of the measured signal;
a first bandpass filter of a passed center frequency f0 into which the first intermediate frequency signal and the first spurious signal are input;
a second local oscillator that outputs the second local oscillation signal (SLO2);
a second mixer that generates a second intermediate frequency signal (SIF2) of a second intermediate frequency fIF2 by performing frequency mixing of the first intermediate frequency signal passing through the first bandpass filter with the second local oscillation signal and generates a second spurious signal (SSP2) by performing frequency mixing of the first spurious signal passing through the first bandpass filter with the second local oscillation signal;
a second bandpass filter of a passed bandwidth W into which the second intermediate frequency signal and the second spurious signal are input, and that allows the second intermediate frequency signal to pass and removes the second spurious signal;
an AD converter that performs AD conversion of the second intermediate frequency signal passing through the second bandpass filter;
and
a signal analysis unit that analyzes the second intermediate frequency signal after the AD conversion performed by the AD converter,
wherein the first intermediate frequency fIF1 is provided as f0+Δf,
the frequency fLO1 of the first local oscillation signal is provided as fc+f0+Δf,
the frequency fLO2 of the second local oscillation signal is provided as f0±fIF2+Δf,
a frequency fSP1 of the first spurious signal is provided as 2×fRF,
a frequency fSP2 of the second spurious signal is provided as |fSP1−f0±fIF2−Δf|, and
the frequency setting unit decides the frequency shift amount Δf that does not establish a relationship of −W/2≤|fSP1−f0±fIF2−Δf|−fIF2≤+W/2, and decides the first intermediate frequency fIF1, the frequency fLO1 of the first local oscillation signal, and the frequency fLO2 of the second local oscillation signal.

13 more elements

A signal analysis method for analyzing a measured signal (SRF) including a frequency component fRF, the signal analysis method comprising:

a frequency setting step (S2) of deciding a first intermediate frequency fIF1, a frequency fLO1 of a first local oscillation signal, and a frequency fLO2 of a second local oscillation signal in accordance with a center frequency fc of the measured signal;
a first local oscillation step (S3) of outputting the first local oscillation signal (SLO1);
a first frequency mixing step (S4) of generating a first intermediate frequency signal (SIF1) of the first intermediate frequency fIF1 by performing frequency mixing of the measured signal with the first local oscillation signal, and generating a first spurious signal (SSP1) including a second harmonic component of the measured signal;
a first bandpass step (S5) of a passed center frequency f0 into which the first intermediate frequency signal and the first spurious signal are input;
a second local oscillation step (S6) of outputting the second local oscillation signal (SLO2);
a second frequency mixing step (S7) of generating a second intermediate frequency signal (SIF2) of a second intermediate frequency fIF2 by performing frequency mixing of the first intermediate frequency signal passing through the first bandpass step with the second local oscillation signal, and generating a second spurious signal (SSP2) by performing frequency mixing of the first spurious signal passing through the first bandpass step with the second local oscillation signal;
a second bandpass step (S8) of a passed bandwidth W into which the second intermediate frequency signal and the second spurious signal are input, the second intermediate frequency signal is allowed to pass, and the second spurious signal is removed;
an AD conversion step (S9) of performing AD conversion of the second intermediate frequency signal passing through the second bandpass step;
and
a signal analysis step (S10) of analyzing the second intermediate frequency signal after the AD conversion in the AD conversion step,
wherein the first intermediate frequency fIF1 is provided as f0+Δf,
the frequency fLO1 of the first local oscillation signal is provided as fc+f0+Δf,
the frequency fLO2 of the second local oscillation signal is provided as f0±fIF2+Δf,
a frequency fSP1 of the first spurious signal is provided as 2×fRF,
a frequency fSP2 of the second spurious signal is provided as |fSP1−f0±fIF2−Δf|, and
in the frequency setting step, the frequency shift amount Δf that does not establish a relationship of −W/2≤|fSP1−f0±fIF2−Δf|−fIF2≤+W/2 is decided, and the first intermediate frequency fIF1, the frequency fLO1 of the first local oscillation signal, and the frequency fLO2 of the second local oscillation signal are decided.

13 more elements

Dependencies are inferred from the claim text.