Integrated microstrip to suspend stripline transition structure and method of fabrication
AssigneeMotorola, Inc.
InventorsKenneth Vern Buer, David Warren Corman
Life of this patent
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Abstract
An integrated microstrip (14) to suspended stripline (24) transition structure and method for fabricating the same provide a transition from microstrip (14) to suspended stripline (24) transmission line with minimal electrical discontinuity and insensitivity due to misalignment. A conductor (10) has a constant width, while gradually tapering voids (44,42) in ground planes (36, 38) provide a suspended stripline (24) transmission medium. The gradually tapering voids (44, 42) provide impedance transformation and minimize discontinuities during transition due to fabrication tolerances.
Claims17
A method for fabricating an integrated microstrip to suspended stripline transition structure, said method comprising the steps of:
- forming a conductor on a first side of a substrate, said conductor having a constant cross-sectional dimension;
- shaping a first void in a top side of a first ground plane, said first void having a gradual taper beginning at a first transition point on said top side of said first ground plane;
- shaping a second void in a bottom side of a second ground plane, said second void having a gradual taper beginning at a second transition point on said bottom side of said second ground plane, said first void and said second void being symmetrical;
- placing a first portion of said conductor and said substrate on said top side of said first ground plane, said first portion defining a microstrip;
- suspending a second portion of said conductor and said substrate over said first void, said second portion defining a suspended stripline;
- and
- placing said second ground plane over said suspended stripline.
An integrated microstrip to suspended stripline transition structure comprising:
- a first ground plane having a first void on a top side, said first void being a gradual taper beginning at a first transition point;
- a conductor having constant cross-sectional dimension;
- a substrate having a first side formed to said conductor, said conductor and said substrate having a first portion placed on said top side of said first ground plane and a second portion suspended over said first void, said first portion defining a microstrip and said second portion defining a suspended stripline;
- and
- a second ground plane suspended above said conductor, said second ground plane having a second void on a bottom side, said second void having a gradual taper beginning at a second transition point.
Dependencies are inferred from the claim text.