Compact 60-GHz IPD-Based Branch-Line Coupler for System-on-Package V-Band Radios

Compact and wideband 3-D IPD butler matrix for millimeter-wave communications

“…used for metal layers (Cu vs. Al) placed on insulating substrates (i.e. glass) [18,29]. But these characteristics make the circuits manufactured in IPD technologies more bulky than their CMOS counterparts.…”

Stripline forward‐wave directional coupler based on double multi‐via mushroom and short‐circuited branch line

“…To improve the integration of the antenna and front‐end, different transmission lines including the rectangular air‐filled coaxial line, suspended stripline, groove gap waveguide, and microstrip line are, respectively, applied for the coupler designs using the machining, 3‐D printing, and printed circuit board (PCB) techniques 1‐6 . Moreover, the integrated passive device technology is used for designing the coupler chips for miniaturization and millimeter‐wave applications 7‐8 . In these couplers, 1,3,5‐8 the hybrid coupler and branch‐line coupler methodologies are commonly applied.…”

“…Moreover, the integrated passive device technology is used for designing the coupler chips for miniaturization and millimeter‐wave applications 7‐8 . In these couplers, 1,3,5‐8 the hybrid coupler and branch‐line coupler methodologies are commonly applied. Besides, the impedance‐transforming concept is used for the 3‐dB coupler, 9 and rat‐race balanced couplers are also proposed with common‐mode suppression for differential system application 10‐11 …”

On-chip X-band branch-line coupler using glass integrated passive device technology

“…To tackle the problem, a number of miniaturised branch-line couplers have been proposed using a printed circuit board (PCB) [1] as well as advanced fabrication processes such as the LTCC and CMOS technologies [2,3]. Thanks to the wafer-level line resolution, the integrated passive device (IPD) technology has also emerged as a promising solution for future packaging and system-in-a-package (SiP) applications [4].…”