Millimeter-wave band spectrum analysis device and analysis method

Patent metadata

Field	Value
Publication number	US-9389255-B2
Application number	US-201414212393-A
Country	US
Kind code	B2
Filing date	Mar 14, 2014
Priority date	Mar 28, 2013
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

An input signal Sx in a first millimeter-wave frequency band higher than 100 GHz is input to a millimeter-wave band filter 20 in which a pair of radio wave half mirrors 30 A and 30 B so as to opposite to each other and which performs a resonance operation. A signal component Sa corresponding to the resonance frequency of the filter is extracted, is mixed with a first local signal L 1 with a fixed frequency, and is converted into a signal in a second frequency band. The converted signal component Sb is mixed with a second local signal L 2 whose frequency is swept and is converted into a signal in a predetermined intermediate frequency band. Then, the level of the signal is detected. The millimeter-wave filter 20 has high selectivity characteristics in a frequency domain higher than 100 GHz and can change its passband center frequency.

First claim

What is claimed is:

1. A millimeter-wave band spectrum analysis device comprising:
a millimeter-wave band filter that includes a transmission line which is formed by a waveguide that propagates electromagnetic waves in a first millimeter-wave frequency band from one end to the other end in a single mode, a pair of planar radio wave half mirrors which are arranged so as to be opposite to each other with a distance therebetween while blocking the inside of the transmission line, transmit some of the electromagnetic waves in the first frequency band, and reflect some of the electromagnetic waves, and resonance frequency change means for changing an electrical length between the pair of radio wave half mirrors to change a resonance frequency of a resonator formed between the pair of radio wave half mirrors in the first frequency band, extracts a signal component in a band having the resonance frequency as a passband center frequency from a signal which is input from one end of the transmission line, and outputs the signal component from the other end;
a frequency conversion unit that mixes the output signal from the millimeter-wave band filter with a first local signal with a fixed frequency to convert the output signal into a signal in a second frequency band lower than the first frequency band;
a spectrum detection unit that converts each frequency component of the signal in the second frequency band which is converted by the frequency conversion unit into each frequency component in a predetermined intermediate frequency band using a second local signal whose frequency can be swept and detects the level of each frequency component; and
a control unit that stores data which associates the resonance frequency with the electrical length between the pair of radio wave half mirrors of the millimeter-wave band filter in advance, changes the passband center frequency of the millimeter-wave band filter so as to cover an observation frequency range on the basis of the data when frequency resolution and a desired observation frequency range of the first frequency band are designated, controls the sweep of the frequency of the second local signal of the spectrum detection unit, and detects a spectrum waveform of a signal in the observation frequency range with the frequency resolution.

2. The millimeter-wave band spectrum analysis device according to claim 1 ,
wherein the control unit has a first control mode which operatively associates a change in the passband center frequency of the millimeter-wave band filter with the sweep of the second local signal of the spectrum detection unit and a second control mode which sweeps the second local signal of the spectrum detection unit in a change step smaller than a change step of the passband center frequency of the millimeter-wave band filter and selects any one of the first control mode and second control mode on the basis of the designated observation frequency range and frequency resolution.

3. The millimeter-wave band spectrum analysis device according to claim 1 ,
wherein the resonance frequency change means of the millimeter-wave band filter has a structure in which the distance between the pair of radio wave half mirrors is changed by a driving device having a stepping motor as a driving source, and
the control unit uses a state in which the distance between the pair of radio wave half mirrors is equal to a predetermined value as a reference state and changes the passband center frequency of the millimeter-wave band filter on the basis of data which associates the resonance frequency with the number of driving pulses of the stepping motor.

4. The millimeter-wave band spectrum analysis device according to claim 2 ,
wherein the resonance frequency change means of the millimeter-wave band filter has a structure in which the distance between the pair of radio wave half mirrors is changed by a driving device having a stepping motor as a driving source, and
the control unit uses a state in which the distance between the pair of radio wave half mirrors is equal to a predetermined value as a reference state and changes the passband center frequency of the millimeter-wave band filter on the basis of data which associates the resonance frequency with the number of driving pulses of the stepping motor.

5. A millimeter-wave band spectrum analysis method comprising:
a step of extracting a signal component in a band having a resonance frequency as a passband center frequency from a signal which is input from one end of a transmission line using a millimeter-wave band filter that includes the transmission line formed by a waveguide which propagates electromagnetic waves in a first millimeter-wave frequency band from one end to the other end in a single mode, a pair of planar radio wave half mirrors which are arranged so as to be opposite to each other with a distance therebetween while blocking the inside of the transmission line, transmit some of the electromagnetic waves in the first frequency band, and reflect some of the electromagnetic waves, and resonance frequency change means for changing an electrical length between the pair of radio wave half mirrors to change a resonance frequency of a resonator formed between the pair of radio wave half mirrors in the first frequency band;
a step of mixing the output signal from the millimeter-wave band filter with a first local signal with a fixed frequency to convert the output signal into a signal in a second frequency band lower than the first frequency band;
a step of converting each frequency component of the signal in the second frequency band which is converted by the step of converting frequency into each frequency component in a predetermined intermediate frequency band using a second local signal whose frequency can be swept and detecting the level of each frequency component; and
a step of storing data which associates the resonance frequency with the electrical length between the pair of radio wave half mirrors of the millimeter-wave band filter in advance, changing the passband center frequency of the millimeter-wave band filter so as to cover an observation frequency range on the basis of the data when frequency resolution and a desired observation frequency range of the first frequency band are designated, controlling the sweep of the frequency of the second local signal, and detecting a spectrum waveform of a signal in the observation frequency range with the frequency resolution.

Assignees

• Anritsu Corp

Inventors

• Fuse Masaaki
• Otani Akihito
• Sekiya Hitoshi

Classifications

• G01R23/165 Primary

  using filters · CPC title

• G01R23/173

  Wobbulating devices similar to swept panoramic receivers · CPC title

• G01R23/16 Primary

  Spectrum analysis; Fourier analysis · CPC title