GB1279063A - Polarisation selector apparatus for use with aerials - Google Patents

Abstract

1279063 Aerials SOC LANNIONNAISE D ELECTRONIQUE 19 April 1971 [5 March 1970] 23196/71 Heading H4A Polarization selector apparatus comprises a six quarter-wavelength hybrid H having four successive ports 1, 2, 3, 4 at quarter-wavelength spacings. The port 1 may be connected by switching circuitry either directly or through a quarter-wavelength line L, to a first terminal. The port 4 is connected directly to a second terminal, and either the port 2 or the port 3 may be connected to a third terminal. As described, switching operations are performed by two relays R 1 , R 2 . Two aerials A 1 , A 2 , which are each inclined at 45 degrees to the horizontal, and are inclined at 90 degrees to each other, are respectively connected to the first and second terminals. A transmitter or a receiver S is connected to the third terminal. When the relay R 1 is in position (a), the quarter-wavelength line L is in circuit and, with the R 2 in position (c), so that the transmitter or receiver S is connected to the port 2, the aerials are phased for waves with vertical linear polarization. If the relay R 2 is changed to position (d), so that the transmitter or receiver S is connected to the port 3, the aerials are phased for waves with horizontal linear polarization. When the relay R 1 is in position (b), so that the line L is not in circuit, the aerials are phased for waves with circular polarization. Whether that polarization is right- or left-handed depends upon the position of the relay R 2 . In other embodiments, the relay R 2 is omitted, and the third terminal is directly connected either to the port 2 (Fig. 2, not shown) or to the port 3.