Three-dimensional confocal imaging for breast cancer detection using CMOS Gaussian monocycle pulse transmitter and 4 × 4 ultra wideband antenna array with impedance matching layer

Abstract

A time-domain reflectometry breast cancer detection system was developed, which was composed of a Gaussian monocycle pulse (GMP) transmitter circuit fabricated by complementary metal oxide semiconductor (CMOS) 65 nm technology and an ultra wide-band (UWB) planar slot antenna array. The center frequency and bandwidth of the antenna were 6 and 9.2 GHz, respectively. The GMP train having the pulse width of 160 ps was generated by the 65 nm CMOS logic circuit with a core area of 0.0017 mm2 and was emitted by the 4 × 4 planar slot antenna array. The fabricated planar 4 × 4 antenna array with the matching layer could resolve the two separate 5 × 5 × 5 mm3 breast tumor phantoms, which were located at the depth of 22 mm with the spacing of 8 mm.

A 2‐ to 12‐GHz 65‐nm transmit/receive CMOS DP8T switching matrix for ultra‐wideband antenna arrays

“…The time delay from transmitting Antenna 1 (Ant1g1 of group 1) to receiving Antenna 4 (Ant4g2 of group 2) depends on the spatial distances between the two antennas and the dielectric constant of the medium. For example, if a DP8T switch is connected with a 4 × 4 antenna matrix as in the previous studies, the distance between these two antennas will be 3.6 cm. Figure shows the 4 × 4 antenna matrix of the previous studies, where the Ant1g1 and Ant4g2 ports can be connected to the no 1 and no 4 antennas, respectively, separated by 3.6 cm.…”

“…The single‐pole–multiple‐throw (SPMT) radio frequency (RF) switch is an important building block in various complementary metal oxide semiconductor (CMOS) control circuits, such as in radar systems, tumor detection in biomedical applications, phase shifters, multibeam applications, and multiband selection communication systems…”

“…Recently, research on microwave radar‐based breast tumor detection systems has gained popularity for eliminating the associated problems of ionized radiation and painful breast compression of X‐ray mammography. In a radar‐based microwave tumor detection system, a 3‐ to 10‐GHz ultra‐wideband (UWB) CMOS‐integrated transmitter (Tx) and receiver (Rx) are used while controlling antennas by the UWB switching matrix . In the previous studies, a conventional mechanical double‐pole–16‐throw switching matrix was utilized to control 16 miniature radar antennas.…”

“…In a radar‐based microwave tumor detection system, a 3‐ to 10‐GHz ultra‐wideband (UWB) CMOS‐integrated transmitter (Tx) and receiver (Rx) are used while controlling antennas by the UWB switching matrix . In the previous studies, a conventional mechanical double‐pole–16‐throw switching matrix was utilized to control 16 miniature radar antennas. Such a mechanical switching matrix is very large in size and expensive, consumes 10 to 100 W of power, and has a large insertion loss of 10 to 18 dB that prevents the development of a low‐cost, low‐power, compact, and portable breast tumor detection system.…”

“…Shin et al and Choi et al reported 4 × 4 crossbar and beam‐forming Butler switches, respectively. Another CMOS beam‐forming Butler switch of an 8 × 8 matrix was discussed in the study of Cetinoneri et al Recently, a 65‐nm DC‐17‐GHz CMOS single‐pole–eight‐throw (SP8T) switch was reported in the studies of Azhari et al and Song et al, in which two SP8T switches were utilized to replace a conventional mechanical switching matrix in a radar‐based tumor detection system to make a compact, low‐power, and portable system.…”