Phase measurement device and method in microwave tomography system

A phase measurement device in a microwave tomography system, comprising:

• a transmit (Tx) frequency generator configured to generate a first frequency signal and a second frequency signal separated by a predetermined discrete frequency from the first frequency signal;
• a local oscillation frequency generator configured to generate a first local oscillation frequency signal separated by an intermediate frequency from the first frequency signal and a second local oscillation frequency signal separated by the intermediate frequency from the second frequency signal;
• a low noise amplifier (LNA) configured to receive a third frequency signal corresponding to the first frequency signal and a fourth frequency signal corresponding to the second frequency signal, low-noise-amplify the received signals, and output the amplified signals;
• a mixer configured to generate a first mixed signal by mixing the third frequency signal and the first local oscillation frequency signal, and generate a second mixed signal by mixing the fourth 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.