Guidance equipment for microwave landing system

Claim 1

Guidance equipment for a microwave landing system, comprising: an azimuth radiating element array producing a first scanning beam for azimuth guidance, said azimuth radiating element array including a plurality of azimuth radiating elements; an elevation radiating element array producing a second scanning beam for elevation guidance, said elevation radiating element array including a plurality of elevation radiating elements; oscillation multiplier means for generating a radio frequency signal; a control circuit outputting a preamble signal and transmission timing signals which are individually assigned to said first scanning beam and said second scanning beam; modulator means for modulating said radio frequency signal with said preamble signal and for transmitting a modulated radio frequency signal together with said radio frequency signal responsive to said transmission timing signals; a plurality of phase shift control means for distributing a plurality of signal power signals which are fed to said plurality of phase shift control means, each of said phase shift control means individually responding to a control signal for controlling a level of signal power and a drive phase applied to one azimuth radiating element of said azimuth radiating element array during a first time period and to one elevation radiating element of said elevation radiating element array during a first time period; power divider means for distributing signal power outputted by said modulator means to said plurality of phase shift control means; and scanning control means for delivering said control signal to each of said plurality of phase shift control means in response to said transmission timing signals and for controlling said plurality of phase shift control means such that at a transmission timing of said preamble signal a radiation pattern characteristic of said elevation radiating element array is changed.