Microstrip phase shifters

• US 6,350,335 B1
• Filed: 10/23/2000
• Issued: 02/26/2002
• Est. Priority Date: 02/16/1999
• Status: Expired due to Term

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: O'Bryan, Henry Miles, Hampel, Karl Georg, Watts, Roderick Kent, Thomson, John
• Primary Examiner(s): MAYES, MELVIN C
• Application Number:
  US09/694,388
• Time in Patent Office: 491 Days
• Field of Search: 156/89.12, 156/89.14, 156/89.16, 427/58, 427/123, 427/126.3, 333/1.1, 333/24.1
• US Class Current: 156/89.14
• CPC Class Codes: H01P 1/181 using ferroelectric devices

Abstract

The specification describes a phase shifting microstrip device in which the ground plane electrode is formed on a substrate surface and a film of ferroelectric material with a thickness less than 200 μm is formed over the ground plane electrode. The microstrip electrode is formed over the film of ferroelectric material to produce a microstrip device with an operating voltage of less than 200 volts.

Claims

1. Method for the manufacture of a ferroelectric device comprising the steps of:

(a) preparing a substrate,

(b) depositing a first metal conductor layer on the substrate,

(c) screen printing an active ferroelectric layer on the first metal conductor layer, the active ferroelectric layer having a thickness in the range 5-20 microns, and having a plurality of holes through the active ferroelectric layer exposing the first metal conductor layor, and

(d) selectively depositing a second metal conductor layer on the active ferroelectric layer, said second metal conductor layer having a first portion contacting the first metal conductor layer through the said holes, and a second portion on the surface of the active ferroelectric layer.

2. The method of claim 1 wherein the active ferroelectric layer comprises Ba_xSr_yTiO₃.

3. The method of claim 2 where said ferroelectric layer further includes MgTiO₃.

4. The method of claim 2 wherein the substrate comprises Ba_xSr_yTiO₃.

5. The method of claim 1 wherein the substrate and the ferroelectric layer are of the same material.

6. The device of claim 1 where the substrate is a laminated structure.

7. Method for the manufacture of a ferroelectric device comprising the steps of:

(a) preparing a Ba_xSr_yTiO₃ ceramic substrate by steps comprising;

(i) forming multilayer interconnections on the surface of a first Ba_xSr_yTiO₃ ceramic tape,

(ii) applying a second Ba_xSr_yTiO₃ ceramic tape over the surface of the first ceramic tape,

(iii) forming a first metal conductor layer on the second Ba_xSr_yTiO₃ ceramic tape,

(iv) co-firing the Ba_xSr_yTiO₃ ceramic tapes to form the substrate,

(b) screen printing a Ba_xSr_yTiO₃ active ferroelectric layer on the substrate, the Ba_xSr_yTiO₃ active ferroelectric layer having a thickness in the range 5-20 microns, and having a plurality of holes through the Ba_xSr_yTiO₃ active ferroelectric layer exposing the first metal conductor layer,

(c) filling the holes with conductor,

(d) firing the Ba_xSr_yTiO₃ active ferroelectric layer and conductor, and

(e) selectively depositing a second metal conductor layer on the Ba_xSr_yTiO₃ active ferroelectric layer.