MICROWAVE STRIPLING CIRCUITS WITH SELECTIVELY BONDABLE MICRO-SIZED SWITCHES FOR IN-SITU TUNING AND IMPEDANCE MATCHING

• US 3,796,976 A
• Filed: 07/16/1971
• Issued: 03/12/1974
• Est. Priority Date: 07/16/1971
• Status: Expired due to Term

• Current Assignee: Harvey C. Nathanson, John R. Davis, Jr., Terrence M.S. Heng
• Original Assignee: Harvey C. Nathanson, John R. Davis, Jr., Terrence M.S. Heng
• Inventors: Nathanson, Harvey C., Heng, Terrence M. S., Davis, John R. Jr.
• Primary Examiner(s): Rolinec, Rudolph V.
• Assistant Examiner(s): Chatmon, Jr., Saxfield
• Application Number:
  US05/163,367
• Time in Patent Office: 970 Days
• Field of Search: 333/11,73S,81A,84M,7
• US Class Current: 333/161
• CPC Class Codes: H01P 1/10 for switching or interrupting in systems using reflection or reradiation of radio, acoustic or other waves G01S7/034
• CPC Class Codes: H01P 5/04 with variable factor of coupling
• CPC Class Codes: H01P 7/084 Triplate line resonators H01P7/088 takes precedence

Abstract

A microstrip line is divided into a number of short sections, each capacitively coupled to its neighbor by a cantilever switch. The coupling of each switch depends on the separation between sections and the spacing between the catilever switch and an adjoining section. The cantilever switches are sufficiently flexible to allow test contact between adjacent sections and is permanently bondable where desired. In such a manner sections having lengths chosen to be predetermined fractions of a desired wavelength are connected together to shift the phase of energy propagating therealong to provide tuning and impedance matching of microstrip circuits.

Claims

1. A stripline conductor for tuning and impedance matching of microwave circuitry comprising, in combination;

a plurality of line sections, each of a length chosen to be a selected fraction of a wavelength;

a plurality of cantilever switches each associated with their respective one of said sections and Having a first portion affixed thereto and a second section extending over but spaced from an adjacent section but which second section can be selectively permanently bonded to said adjacent section whereby the phase shift along said stripline is a function of the number of switches which are bonded closed.

2. A microwave stripline of substantially one wavelength at the desired frequency of operation comprising, in combination;

a plurality of sections, each of a length chosen to be a selected fraction of said wavelength;

a plurality of cantilever switches each associated with a respective one of said sections and capacitively coupling said one of said sections to an adjacent section;

each said cantilever switch having a first portion affixed to said one of said sections and a second portion extending over but spaced from its adjacent section;

the capacitive coupling between sections being related to the separation between adjacent sections and the space between the overhanging second portion and said associated adjacent section as well as the extent to which said second section extends over said associated adjacent section;

said plurality of cantilever switches being sufficiently flexible to effect a test contact between adjacent portions upon application of slight pressure thereupon;

each of said plurality of cantilever swithces being selectively, permanently bondable to its associated adjacent section whereby the capacitative coupling between adjacent sections is electrically shorted and the energy propagating along said stripline is shifted in phase in accordance with the number of sections so connected to accomplish tuning and impedance matching.

3. The subject matter of claim 2 including impedance matching means at each end of said stripline.

4. The subject matter of claim 3 wherein said impedance matching means includes quarter-wave transformers.

5. The subject matter of claim 2 wherein the neighboring sections are at least twice the length of their associated cantilever switch length.

6. A microelectronic component comprising, in combination;

a substrate;

a first pattern of conductors on a surface of said substrate;

a plurality of cantilever switches each associated with a respective one of said conductors and having a first portion affixed thereto and a second portion extending over but spaced from an adjacent conductor;

each of said cantilever switches being sufficiently flexible to effect a test contact between adjacent conductors;

each of said flexible switches being selectively, permanently bondable to its associated adjacent conductor to widen the current path whereby adjacent conductors are selectively connected in parallel circuit relationship whereby the width of the resultant electrical path is increased.

7. A method of making a microwave stripline with selectively cold-flow bondable micro-sized switches for in-situ tuning on a substrate comprising the steps of;

depositing a first continuous metal layer on a surface of said substrate;

depositing a pattern of conductive sections of a second metal layer on said first layer to define switch gaps between said sections;

depositing a layer of spacing material in the gaps between said sections and onto a portion of each said section;

depositing a third metal layer over a portion of each said section and a part of said spacing material to an extent that the third metal layer overlaps a part of said second metal layer;

removing the spacers and excess metalizations by successive etchings to form the cantilever switches.

8. The method of claim 7 wherein;

said substrate is a member selected from the group consisting of sapphire, alumina and quartz.

9. The method of claim 8 wherein the second and third layers are of gold.

10. The method of claim 9 wherein said second and third metals are the members selected from the group consisting of nickel, copper, silver, cadmium, gold, tin, palladium, aluminum and nickel-iron alloys.

11. A microwave stripline switch arrangement for use at an operating wavelenGth, comprising:

a first stripline section, at least a second stripline section spaced from said first section, a cantilever switch section connected to said first stripline section and extending over and spaced from said second stripline section and connectable therewith, said sections being of a combined length to effect phase shifting of microwave energy of said wavelength when contact is effected between said cantilever switch section and said second stripline section.