Toward an Electronically Scanned Imager for Microwave Imaging of the Compressed Breast

Abstract

Microwave imaging shows promise for breast cancer screening and detection, offering non-ionizing radiation, low-cost, compact electronics, and compatibility with fast image reconstruction methods. However, clinical adoption is limited, largely due to the need for efficient data acquisition systems with high dynamic range and low signal clutter. This work introduces a novel ultra-wideband (UWB) electronically switched breast microwave imager that multiplexes hundreds of active antennas on the receiver side at a single-tone intermediate frequency (IF) to alleviate the limitations of the UWB radio frequency (RF) switching. The research is structured around three main contributions. First, a 16×16 planar UWB receiving (Rx) array of shielded slot antennas is developed on printed circuit board (PCB) technology, with each antenna equipped with a low-noise amplifier (LNA). Due to space constraints, the remaining front-end circuitry, including the mixers and the IF switching network, are incorporated on separate boards, requiring seamless board-to-board RF transitions. To this end, the second contribution focuses on a low-cost, mechanically robust, low-crosstalk interconnection solution using high-pin-density high-speed vertical connectors (HSVCs) widely adopted in computer technology to link the Rx array to its front-end circuitry. Finally, an electronically switched 16×16 UWB transmitting (Tx) array is proposed, also leveraging HSVCs to enable efficient integration with various RF feed networks, providing flexible illumination scenarios for the microwave breast imager. Together, these innovations take a step forward in making UWB microwave imaging clinically viable for the non-invasive, real-time detection of breast cancers