Browsing by Author "Karnfelt, Camilla"

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Design, Fabrication, and Characterization of Novel Vertical Coaxial Transitions for Flip-Chip Interconnects
(2009-05-01)
Wu, Wei-Cheng
;
Chang, Edward Yi
;
Hwang, Ruey-Bing
;
Hsu, Li-Han
;
Huang, Chen-Hua
In this paper, a novel transition design using vertical "coaxial transition" for coplanar waveguide (CPW-to-CPW) flip-chip interconnect is proposed and presented for the first time. The signal continuity is greatly improved since the coaxial-type transition provides more return current paths compared to the conventional transition in the flip-chip structure. The proposed coaxial transition structure shows a real coaxial property from the 3-D electromagnetic wave simulation results. The design rules for the coaxial transition are presented in detail with the key parameters of the coaxial transition structure discussed. For demonstration, the back-to-back flip-chip interconnect structures with the vertical coaxial transitions have been successfully fabricated and characterized. The demonstrated interconnect structure using the coaxial transition exhibits the return loss below 25 dB and the insertion loss within 0.4 dB from dc to 40 GHz. Furthermore, the measurement and simulation results show good agreement. The novel coaxial transition demonstrates excellent interconnect performance for flip-chip interconnects and shows great potential for flip-chip packaging applications at millimeter waves.
Flip-Chip-Based Multichip Module for Low Phase-Noise V-Band Frequency Generation
(2010-09-01)
Hsu, Li-Han
;
Kuylenstierna, Dan
;
Kozhuharov, Rumen
;
Gavell, Marcus
;
Karnfelt, Camilla
This paper reports on a flip-chip (FC)-based multichip module (MCM) for low phase-noise (PN) V -band frequency generation. A high-performance x8 GaAs metamorphic high-electron mobility transistor monolithic microwave integrated circuit (MMIC) multiplier and a low PN 7-GHz GaAs InGaP heterojunction bipolar transistor (HBT) MMIC oscillator were used in the module. The microstrip MMICs were FC bonded to an Al(2)O(3) carrier with patterns optimized for low-loss transitions. The FC-based module was experimentally characterized to have a PN of -88 dBe/Hz @ 100-kHz offset and -112 dBc/Hz @ 1-MHz offset with an output power of 11 dBm. For comparison, the MMICs were also FC bonded as individual chips and the performance was compared with the bare dies without FC bonding. It was verified that the FC bonding has no detrimental effect on the MMIC performance. The tests revealed that the FC module provided improved performance. To our best knowledge, this is the first FC-based module for millimeter-wave frequency generation. The module also presents one of the best PN reported for millimeter-wave frequency sources.