Soldered hot-via E-band and W-band power amplifier MMICs for millimeter-wave chip scale packaging

Novel and realistic application of hot-via interconnects to millimeter-wave active and power MMICs is demonstrated for the first time. Power amplifier MMICs in the 80- and 100-GHz range were successfully designed, assembled, and characterized for wire-bond free chip interconnect technology. With hot-via RF transitions, compact E-band power amplifier MMICs directly soldered onto evaluation boards demonstrate 22-dB gain and over 28-dBm output power in the ETSI band of 81-86 GHz, with little performance degradation compared to reference circuits probed with traditional front-side RF pads. Similarly, a broadband amplifier, when interconnected to its matching PCB, delivers 13-dB of gain in the W-band, and 21-dBm P1dB. To the author's knowledge, this work represents the highest frequency demonstration of any soldered millimeter-wave hot-via active circuits onto standard PCBs, with remarkable measured power performance, closely equaling that of ideally front-side RF probed PA MMICs.