  A compact quasi-Yagi antenna with a modified ground plane is designed for a
through-wall radar (TWR) on-chip. A slot-based ground plane modification in the
proposed antenna results in significant miniaturization with an increase in the
impedance bandwidth by 44.62%. The antenna has a high directivity of 9.02 dBi
and a front-to-back ratio of 25.76 dB at 2.4 GHz. Based on experiments in
real-world deployment scenarios, the performance of the proposed quasi-Yagi
antenna is found to be comparable to that of a Vivaldi antenna and a
commercial-off-the-shelf (COTS) horn antenna. Spectrogram-based signatures of a
moving person behind a wooden partition and a 40 cm thick masonry wall are
successfully obtained using the designed antenna, demonstrating the suitability
of the quasi-Yagi antenna for portable applications using a radar-on-chip.
