Very Compact High-gain Broadband Low-noise Amplifier in InP HEMT Technology

We successfully developed an InP high electron mobility transistor (HEMT) low-noise amplifier (LNA) using multi-layer transmission lines. The fabricated five-stage LNA achieved a 43 dB gain with a noise figure (NF) of 1.9 dB at 23 GHz and a gain of more than 40 dB from 18 to 43 GHz. The maximum gain was 49.5 dB at 32 GHz and the chip size was only 1.8 times 0.9 mm², resulting in a gain density of 30.5 dB/mm². To the best of our knowledge, this gain density is the highest performance in any Ka-band LNA reported to date. In addition, the design accuracy of the LNA was also demonstrated