Active GNSS antenna implemented with two-stage LNA on high permittivity substrate

We propose a small active antenna to receive Global Navigation Satellite System (GNSS) signals, i.e., Global Positioning System (GPS) L1 (1,575MHz) and Russian Global Navigation Satellite System (GLONASS) L1 (1,600 MHz) signals. A two-stage low-noise amplifier (LNA) with more than 27 dB gain is implemented in the bottom layer of a three-layer antenna package. In addition, a hybrid coupler is used to combine signals from pair of proximately coupled orthogonal feeds with 90° phase difference to achieve the circular polarization (CP) characteristic. Three layers of high permittivity (ε_r= 10) substrates are stacked and effectively integrated to have a small dimension of 64 mm×64 mm×7.42 mm (including both circuit and antenna). The reflection coefficient of the fabricated antenna at the target frequency is below-10 dB, the measured antenna gain is above 26 dBic and the measured noise figure is less than 1.4 dB.