Vistar Telecommunications Inc.

Her Majesty the Queen in Right of Canada, As Represented by the Minister

Resonance Microwave Systems Inc.

David J Roscoe

Philippe Lafleur

James Stuart Wight

Jim Wight

Michael Cooper

Brian Clarke

Philippe LaFleur

A tunable resonant system includes an electric element, and a core having a controllable parameter that determines the resonant frequency of the system. In order to tune the resonant system to a desired frequency, a low power, narrowband signal is applied at a selected frequency to the electric element. The reflected or transmitted power is measured and the value of the controllable parameter adjusted to vary the resonant frequency of the system in a closed loop until the reflected power is at a minimum.

Closed loop antenna tuning system

A low profile antenna with high gain at low elevations suitable for satellite communications consists of a helical loop with turns tightly spaced to provide a strong coupling therebetween. The pitch is typically 1 to 2 degrees. The helical loop behaves like a travelling-wave loop antenna.

Low profile mobile satellite antenna

An integrated dual-mode antenna including a quadrifilar antenna and a collocated monopole antenna. The integrated antenna is compact and unencumbered by signal blockage or isolation problems.

Integrated satellite/terrestrial antenna

An antenna array is disclosed wherein radiators are parasitically coupled to each other, forming an efficient feed network. Parasitic coupling of patches is arranged so that some patches are fed by a plurality of other patches which are parasitically coupled thereto. The resulting array is low profile and high gain. By positioning patches on different layers with different dimensions, a broadband design for the antenna array is achieved.

Multiple parasitic coupling to an outer antenna patch element from inner

In the past, parabolic offset reflector antennas were fed a signal through a corrugated horn in order to optimize field distribution and polarization at the reflector. It has been found that cost savings and other advantages are realized by using an array of radiating patches. The geometrical placement of the radiating patches and the power distribution to each patch is arranged such that radiated energy from the patches sums at the reflector surface to produce the predetermined field distribution and polarization.

Growing community of inventors

Dunrobin, Canada

David J Roscoe