A full E-band low noise amplifier realized by using novel wafer-level chip size package technology suitable for reliable flip-chip reflow-soldering

Cost effective E-band Low Noise Amplifier (LNA) using a three-dimensional (3-D) MMIC technology and wafer level chip size package (WLCSP) technology is presented. The reflow-soldering compatibility of the technology makes MMIC assembly on PCB very simple and significantly contributes to mass production of receivers and transmitters. The applied 3-D MMIC design effectively shrinks the die sizes. The newly designed LNA exhibited an on-chip gain of 22.5 ± 1 dB and a noise figure of 4.0 ± 0.3 dB in the full E-band. The measurements of the assembled LNA, including extended transmission lines on PCB, exhibited a gain of 21 ± 1 dB and a noise figure of 4.6 ± 0.2 dB. Eliminating the extended transmission line losses of about 0.3 dB × 2, the noise figure increase due to assembly was only 0.3 dB. These results show that the LNA using the 3-D WLCSP technology is valuable for E-band application in terms of not only cost reduction but also practical performance achievement.