Global Positioning System (GPS) is used in various fields such as communications systems, transportation systems, e-commerce, power plant systems, and up to various military weapons systems recently. However, GPS receiver is vulnerable to jamming signals as the GPS signals come from the satellites located at approximately 20,000 km above the earth. For this reason, various anti-jamming techniques have been developed for military application systems especially and it is also required for commercial application systems nowadays. In this paper, we proposed a dual-channel Global Navigation Satellite System (GNSS) RF ASIC for digital pre-correlation anti-jam technique. It not only covers all GNSS frequency bands, but is integrated low-gain/attenuation mode in low-noise amplifier (LNA) without influencing in/out matching and 14-bit analogdigital converter (ADC) to have a high dynamic range. With the aid of digital processing, jamming to signal ratio is improved to 77 dB from 42 dB with proposed receiver. RF ASIC for anti-jam is fabricated on a 0.18-μm complementary metal-oxide semiconductor (CMOS) technology and consumes 1.16 W with 2.1 V (low-dropout; LDO) power supply. And the performance is evaluated by a kind of test hardware using the designed RF ASIC.Keywords: GNSS, anti-jamming, RF ASIC, CMOS, high dynamic-range receiver type of jamming signal, but it is a strong threat since all the position and time information based on GPS could be disturbed (Hu & Wei 2009). Jamming signals could induce significant disturbance in the civilian fields based on GPS as well as jamming for the military weapon systems. Thus, preparation for this incident is needed. For the removal of jamming signals, various studies have been performed such as an antenna-based anti-jamming technique and a digital signal processing technique (Abimoussa & Landry 2000, Amin & Sun 2005. To apply a technique for the removal of jamming signals, satellite signals that are smaller than thermal noise and jamming signals that are relatively significantly large need to be converted into digital signals without distortion and sent to a jamming removal signal processing part. Therefore, to implement an anti-jamming function, the RF part of a Global Navigation Satellite System (GNSS) receiver needs to have low-noise characteristics as 116 JPNT 4(3), 115-122 (2015) http://dx.doi.org/10.11003/JPNT.2015.4.3.115well as wider dynamic range and linearity compared to an existing general GNSS receiver (Moulin et al. 1998). In this study, high-sensitivity/high-resolution RF ASIC with a wide dynamic range was designed and manufactured so that it could be used for the implementation of a jamming signal removal function, and an anti-jamming device based on digital signal processing that removes narrowband jamming signals in the frequency domain was implemented and the performance was verified.
DESIGN OF RF ASIC FOR AN ANTI-JAMMING GNSS RECEIVERIn a general GNSS receiver, the RF front-end appropriately amplifies and filters satellite signals received at a signal ...
