A low-cost high performance GaAs MMIC package using air-cavity ceramic quad flat non-leaded package up to 40 GHz

A novel low-cost QFN (quad flat non-leaded) package is introduced for GaAs MMIC packaging. The air-cavity QFN package is designed and implemented with an HTCC process using alumina substrate. To operate the package up to 40 GHz, several key methods are proposed in this paper. A low noise and a buffer amplifier are packaged for practical application examples and compared with bare die measurements to verify the QFN package performance. A maximum of 4.5 dB insertion loss degradation occurred at 40 GHz. To authors' knowledge, this is the highest operating frequency for QFN type packages with low loss ever reported.