Hidden chamber detector

A hidden chamber detector, comprising:

• a linear frequency modulated continuous wave (LFMCW) radar including a transmitter and a receiver;
• a synthetic aperture radar (SAR) imaging processor;
• and
• a time division multiple access (TDMA) multiple input multiple output (MIMO) antenna array, including a plurality of transmitting and receiving (Tx-Rx) antenna pairs formed by a plurality of transmitting (Tx) antenna elements arranged in a row and separated by a distance of two wavelengths of an operating frequency and a plurality of receiving (Rx) antenna elements arranged in a row in parallel with the row of the plurality of Tx antenna elements and separated by a distance of one wavelength of the operating frequency, a single-pole multiple-throw (SPMT) Rx switch configured between the receiver and the plurality of Rx antenna elements, and a SPMT Tx switch configured between the transmitter and the plurality of Tx antenna elements, wherein:
• a Tx-Rx antenna pair is selected, by controlling the SPMT Tx switch and the SPMT Rx switch in a time division manner, from the plurality of Tx-Rx antenna pairs to serve as a Tx antenna and an Rx antenna for the LFMCW radar;
• the LFMCW radar is configured to transmit a radar signal amplified by a power amplifier through the Tx antenna, receive an echo signal through the Rx antenna, convert the received echo signal to a baseband signal, collect baseband samples, and send the collected samples to the SAR imaging processor;
• and
• the SAR imaging processor is configured to receive the collected baseband samples of the echo signal, collect structure/configuration of the TDMA MIMO antenna array and radar range scanning information, and form an SAR image based on the collected baseband samples, the structure/configuration of the TDMA MIMO antenna array, and the radar range scanning information.