A Passive STAR Microwave Circuit for 1-3 GHz Self-Interference Cancellation Conference

Silva, UD, Pulipati, S, Venkatakrishnan, SB et al. (2020). A Passive STAR Microwave Circuit for 1-3 GHz Self-Interference Cancellation . 2020-August 105-108. 10.1109/MWSCAS48704.2020.9184595

cited authors

  • Silva, UD; Pulipati, S; Venkatakrishnan, SB; Bhardwaj, S; Madanayake, A


  • Simultaneous transmit and receive (STAR) allows full-duplex operation of a radio, which leads to doubled capacity for a given bandwidth. A circulator with high-isolation between transmit and receive ports, and low-loss from the antenna to receive port is typically required for achieving STAR. Conventional circulators do not offer wideband performance. Although wide-band circulators have been proposed using parametric, switched delay-line/capacitor, and N-path filter techniques using custom integrated circuits, these magnet-free devices have non-linearity, noise, aliasing, and switching noise injection issues. In this paper, a STAR front-end based on passive linear microwave circuit is proposed. Here, a dummy antenna located inside a miniature RF-silent absorption chamber allows circulator-free STAR using simple COTS components. The proposed approach is highly-linear, free from noise, does not require switching or parametric modulation circuits, and has virtually unlimited bandwidth only set by the performance of COTS passive microwave components. The trade-off is relatively large size of the miniature RF-shielded chamber, making this suitable for base-station side applications. Preliminary results show the measured performance of Tx/Rx isolation between 25-60 dB in the 1.0-3.0 GHz range, and 50-60 dB for the 2.4-2.7 GHz range.

publication date

  • August 1, 2020

Digital Object Identifier (DOI)

start page

  • 105

end page

  • 108


  • 2020-August