Patent ID: 9678124
Date: 2017-06-13
CPC Classifications: G01N,G01R

Claim:
1. A phase measurement device in a microwave tomography system, comprising: a reference frequency generator configured to generate a reference frequency signal; a transmit (Tx) frequency generator configured to generate a first continuous wave frequency signal using the reference frequency signal and to generate a second continuous wave frequency signal using the reference frequency signal, the first continuous wave frequency signal and the second continuous wave frequency signal being separated by a predetermined frequency amount and further configured to transmit from a transmit antenna the first continuous wave frequency signal and the second continuous wave frequency signal; a local oscillation frequency generator that receives the reference frequency signal from the reference frequency generator and is configured to generate a first local oscillation frequency signal using the reference signal and is configured to generate a second local oscillation frequency signal using the reference signal, the second local oscillation frequency signal being separated from the second continuous wave frequency signal by a predetermined intermediate frequency amount; a low noise amplifier (LNA) configured to receive from a receive antenna a first receive frequency signal corresponding to the first continuous wave frequency signal and a second receive frequency signal corresponding to the second continuous wave frequency signal, to low-noise-amplify the first receive frequency signal and the second receive frequency signal, and to output a respective amplified first receive frequency signal and amplified second receive frequency signal; a mixer configured to generate a first mixed signal by mixing the amplified first receive frequency signal and the first local oscillation frequency signal, and generate a second mixed signal by mixing the amplified second receive frequency signal and the second local oscillation frequency signal; an intermediate frequency (IF) filter configured to generate a first IF signal obtained by filtering an IF band from the first mixed signal, and generate a second IF signal obtained by filtering the IF band from the second mixed signal; a phase measurement unit configured to measure a first phase value from the first IF signal, and measure a second phase value from the second IF signal; and an unwrapped phase calculation unit configured to determine an unwrapped phase value based on a first phase difference calculated from a difference between the first and second phase values and a second phase difference corresponding to the discrete frequency.