A 0.18-μm CMOS X-band shock wave generator with an on-chip dipole antenna and a digitally programmable delay circuit for pulse beam-formability

In this paper, we present a 0.18-μm CMOS fully integrated X-band shock wave generator (SWG) with an on-chip dipole antenna and a digitally programmable delay circuit (DPDC) for pulse beamformability in short-range and hand-held microwave active imaging applications. This chip includes a SWG, a 5-bit DPDC and an on-chip wideband meandering dipole antenna. By using an integrated transformer, output pulse of the SWG is sent to the on-chip meandering dipole antenna. The SWG operates based on damping conditions to produce a 0.4-V peak-to-peak (p-p) pulse amplitude at the antenna input terminals in HSPICE simulation. The DPDC is designed to adjust delays of shock-wave outputs for the purpose of steering beams in antenna array systems. The wide-band dipole antenna element designed in the meandering shape is located in the top metal of a 5-metal-layer 0.18-μm CMOS chip. By simulating in Momentum of ADS 2009, the minimum value of antenna's return loss, S 11, and antenna's bandwidth (BW) are -19.37 dB and 25.3 GHz, respectively. The measured return loss of a stand-alone integrated meandering dipole is from -26 dB to -10 dB with frequency range of 7.5-12 GHz. In measurements of the SWG with the integrated antenna, by using a 20-dB standard gain horn antenna placed at a 38-mm distance from the chip's surface, a 1.1-mVp-p shock wave with a 9-11-GHz frequency response is received. A measured 3-ps pulse delay resolution is also obtained. These results prove that our proposed circuit is suitable for the purpose of fully integrated pulse beam-forming system.