An On-Chip Frequency-Reconfigurable Antenna For Q-Band Broadband Applications

This letter presents the design of a Q-band on-chip antenna with broadband characteristic using a standard 0.18- μm CMOS silicon-on-insulator process. A pair of on-chip switches is introduced in this design to implement the antenna with frequency reconfigurability, in order to enhance the bandwidth of the antenna. A small-signal equivalent circuit of this switch is illustrated in this letter, and an optimized gate width of the switch transistor is selected to achieve a tradeoff between the gain and the bandwidth of the proposed antenna. By changing the state of the on-chip switches, a measured –10-dB bandwidth from 29.5 to 51.0 GHz is achieved by this antenna, which has covered the whole Q-band frequency. A measured peak gain of 3.3 dBi is observed at 45 GHz, and a very compact chip size of 1.1 × 1.7 mm2 is achieved by the proposed antenna in this work.