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Selection combining diversity system with antennas mounted on windshield and backlite of a vehicle is proposed for satellite digital audio radio applications. Standalone exterior mount antennas on metallic vehicles perform well for satellite digital audio radio applications, but for composite body vehicles or interior mount antennas, antenna performance becomes a real issue. Proposed on-glass two-antenna diversity is one solution for such applications. The antenna correlation is calculated using the S-parameters of the antennas and found to be very low due to many wavelengths separation between the antennas. Design of low noise amplifier, which has sub 1 dB noise figure and good P1dB due to strong cellular signals, is also detailed. A diversity receiver is described and ride tests are performed to assess the performance of the diversity system in real-time, under weak satellite signal environment which is regarded as the most challenging reception condition. [ABSTRACT FROM AUTHOR]

This paper presents an integrated 802.11a compliant receiver integrated circuit (IC), which is capable of processing four antenna signals using RF multiple-input multiple-output (RF-MIMO) schemes. Following four low-noise amplifiers, the weighting is performed using Cartesian vector modulators, whose output signals are combined and down-converted. The baseband filters, variable gain amplifiers (VGAs), a quadrature voltage-controlled oscillator, and digital interfaces are integrated. Experimental results demonstrate the performance of the individual components, as well as the RF-MIMO capabilities of the whole chip. The IC achieves a receiver noise figure of 3.6 dB, a phase noise of -\113 dBc/\Hz at 1-MHz offset, and an equivalent Cartesian weighting precision of 6\,\times\,6 bit. An RF input signal of up to -\35.3 dBm (1-dB compression) can be processed, while the maximum RF path gain amounts to 28.6 dB. The baseband VGA provides further 9–61-dB gain in 64 steps. [ABSTRACT FROM PUBLISHER]