DEVELOPMENT OF UHF SWITCH FOR LES-6 SATELLITE
Abstract
A UHF switch matrix was developed for the LES-6 satellite to electronically despin the antenna beam as the satellite rotated on its axis. Initially, a study was carried out to determine the optimum antenna system and switch configuration for the constraints of satellite geometry and minimal complexity. Two such switch matrices, operated by logic circuits and sun and earth sensors, were used on the satellite, one to excite two adjacent of eight pairs of antenna dipoles, and the other to excite two adjacent of eight pairs of cavity-backed slots. The polarizations of the signals from the dipoles and slots are orthogonal and by adjusting the phase difference to 90 degrees, the satellite will, in normal operation transmit and receive on right-hand circular polarization. Furthermore, by squinting the beam formed by two element pairs +11.25 degrees or -11.25 degrees from the center line of the element pairs, any of 16 beams can be formed which are equally spaced in azimuth about the satellite. Each switch consists of three parts, namely, a hybrid to divide the input power into two equal parts, a 2P2T section which switches phase, and two SP4T sections to switch on two antenna pairs. The switch was built in strip transmission line using PIN diodes in series with the inner conductor as the switching element.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 04, 1969
- Accession Number
- AD0710612
Entities
People
- Robert N. Assaly
Organizations
- Massachusetts Institute of Technology