Kai L Hansen

US Patent:

47647019, Aug 16, 1988

Filed:

Dec 30, 1986

Appl. No.:

6/947655

Inventors:

Michael J. Garbacz - Norridge IL
Kai Hansen - Arlington Heights IL

Assignee:

Zenith Electronics Corporation - Glenview IL

International Classification:

H01L 4108

US Classification:

310313R

Abstract:

A multichannel surface acoustic wave encoder/decoder having a common electrical input is designed so that the insertion losses of the channels differ despite the apparent design constraint of closely matched channel output impedances. The input transducing device or SAW transmitter is divided into individual transducers (or into subtransducers) having different numbers of finger overlaps, thus achieving different acoustic output levels which in turn result in different insertion losses for different channels. The finger spacing of the SAW transmitters can differ between the respective input transducers or subtransducers so as to optimize the center frequency of each channel.

US Patent:

43792740, Apr 5, 1983

Filed:

Aug 7, 1981

Appl. No.:

6/290649

Inventors:

Kai Hansen - Arlington Heights IL

Assignee:

Zenith Radio Corporation - Glenview IL

International Classification:

H03H 972
H03H 964

US Classification:

333194

Abstract:

An acoustic surface wave filter is described for receiving one of two electrical signals at either of a pair of input ports and for providing a filtered electrical signal at a common output port. The filter includes a pair of input electro-acoustic transducers on a substrate, each coupled to one of the input ports, for launching surface waves in response to an electrical input signal. Each of the input transducers is associated with a multistrip coupler and an output transducer for converting the surface waves to an electrical output signal. The layout and geometry of the filter components are such that all surface waves are launched in a direction which is oblique to the substrate boundaries to reduce interference due to reflected surface waves. The layout and geometry also result in a relatively small substrate and a simultaneous reduction of insertion loss.

US Patent:

43365159, Jun 22, 1982

Filed:

Oct 10, 1980

Appl. No.:

6/195998

Inventors:

Adrian J. DeVries - Mount Prospect IL
Kai Hansen - Arlington Heights IL

Assignee:

Zenith Radio Corporation - Glenview IL

International Classification:

H03H 964
H03H 972

US Classification:

333195

Abstract:

In order to avoid spurious responses at the third harmonic of the signal frequency, a surface acoustic wave filter employs a multi-strip track coupler in which the spacing d of the elements is an integral multiple I of the acoustic wavelength. lambda. of the third harmonic. When the condition d=I. lambda. is satisfied, the coupler blocks transmission of the third harmonic from the input transducer track to the output transducer track. This basic principle can also be used to block other frequencies.