POLARIZATION-INDEPENDENT RECEIVER

• Main Authors: TOMESEN; MARKUS T, HOOIJMANS; PIETER W
• Format: Patent
• Language: English
• Published: 18.08.1992
• Subjects: BASIC ELECTRONIC CIRCUITRY; DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TOANOTHER; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION

For obtaining an output signal which is independent of the polarization direction of the received signal in a receiver for polarized electromagnetic signals, the received signal is split up into two components having a mutually orthogonal polarization direction before these signals are converted to an intermediate frequency. For combining, subsequent to demodulation, the two intermediate-frequency signals to a baseband signal which is independent of the polarization direction, a demodulator is used having a quadratic relation between input and output signals. For obtaining this quadratic relation, the intermediate-frequency signal is split up by an amplifier 20 into two signals having a mutually identical amplitude and mutually opposite signs. Consequently, the odd order terms in the sum of the currents through the diodes 27 and 28 will have opposite signs relative to the odd order terms in the sum of the currents through the diodes 36 and 37. By determining the sum of the currents through all four diodes, the odd order terms will cancel each other out so that only the even order terms of which the quadratic term is the most important will remain so that the desired quadratic relation is obtained.