This paper presents the analysis and design of a 35-GHz high-gain phase shifter with 360° continuous phase shifting. To enhance the phase shift range, a hybrid $\pi $ -network realized by combining the electrical tuning through capacitors and magnetic tuning through transformers is developed. The phase shift modules are inserted between the vertically stacking transistors to achieve the embedded phase shifting with the minimum loss. Furthermore, the Gm stages offer additional signal gain to suppress attenuation in the passive phase shifter. The capacitive neutralization technique is utilized to further increase the gain and enhance stability. This prototype, fabricated in a 28-nm CMOS process, demonstrates a 360° continuous phase shift with a maximum gain of 25.6 dB and a minimum noise figure of 4.1 dB. It consumes 26-mW power with a supply voltage of 0.9 V and 1.25 mm $\times0.75$ mm chip area.
An ultra compact monostatic two-channel radar MMIC at 160 GHz with enhanced angle estimation accuracy is presented. The MMIC is built up of two transceivers as well as two chip integrated antennas. The small antenna aperture of a quarter wavelength is enhanced by applying a biomimetic antenna array. As a consequence, the MMIC only occupies a chip area of 2.40×1.15 mm2. Radar measurements are performed to evaluate the angle estimation capability of the MMIC and it is shown that the accuracy of the angle estimation is enhanced by a factor of 2.2 by using the biomimetic antenna system.
This paper reports on a planar transition from 1 mm coax to the fundamental mode of a polystyrene rectangular dielectric waveguide (DWG), covering frequencies from 50 GHz to 85 GHz. Two back-to-back transitions connected by a 12 cm piece of waveguide with tapered points were measured, demonstrating an insertion loss between the microstrip line and the dielectric waveguide of about 2 dB, which agrees well with simulated values.The structure consists of a 1 mm coaxial board edge connector feeding a microstrip line on a 4 mil thick liquid crystal polymer (LCP) substrate, followed by a vialess transition from microstrip to slotline patterned on the other side of the substrate. The slotline then tapers out and feeds a tapered DWG that is connected to the LCP board by inserting it into a slit along the center of the waveguide.
