Coplanar waveguide-mounted flip chip having coupled ground conductors

• US 5,668,512 A
• Filed: 06/12/1996
• Issued: 09/16/1997
• Est. Priority Date: 09/26/1994
• Status: Expired due to Term

• Current Assignee: Endwave Corp (Renesas Electronics Corporation)
• Original Assignee: Endgate Corp (Renesas Electronics Corporation)
• Inventors: Stoneham, Edward B., Mohwinkel, Clifford A., Johnson, Edwin F.
• Primary Examiner(s): GENSLER, PAUL L
• Application Number:
  US08/662,693
• Time in Patent Office: 461 Days
• Field of Search: 333/238, 333/246, 333/247, 333/128, 330/286, 330/295, 257/664, 257/691, 257/728, 257/778
• US Class Current: 333/247
• CPC Class Codes: H01L 2223/6644 Packaging aspects of high-frequency amplifiers
• CPC Class Codes: H03F 2200/372 Noise reduction and elimination in amplifier
• CPC Class Codes: H03F 3/604 using FET's

Abstract

A radio-frequency power amplifier includes a multiple-FET chip that is flip mounted on a connection region of a substrate. An input impedance-matching network is also mounted on the substrate. The network includes a coplanar waveguide having an elongate waveguide signal conductor for each gate terminal on the FET chip with a distal end spaced from the connection region and a proximal end in the connection region. The distal ends are connected to a single base input conductor. The proximal ends are flip mounted to respective ones of gate terminals of the FET chip. A capacitor couples each of the input signal conductor distal ends to an adjacent ground conductor. The signal conductors and capacitors provide a selected impedance at a selected frequency. The capacitors may be on a separate chip flip mounted to the waveguide signal and ground conductors, and may be formed as coplanar waveguides with open-ended signal conductors. An output coplanar waveguide includes, for each drain terminal, an output signal conductor having an end in the connection region that is electrically connected to the flip mounted FET chip. This waveguide also has a length selected to provide desired impedance matching and may also have other means of impedance matching. The ground conductors of each coplanar waveguide are coupled together in the connection region.

Claims

1. A coplanar waveguide-based circuit structure comprising:

an electrically insulating substrate having a planar face with a connection region;

a first coplanar waveguide mounted on said substrate face and having first and second, spaced-apart coplanar ground conductors, and a first signal conductor coplanar with said ground conductors and positioned between and spaced from said first and second ground conductors, said signal conductor and said first and second ground conductors extending into said connection region, said first and second ground conductors being coupled together in said connection region; and

an integrated circuit flip mounted on said connection region of said substrate with a first terminal flip mounted to one of said ground conductors and a second terminal flip mounted to said signal conductor, said waveguide conducting electrical current relative to said integrated circuit.

2. A circuit structure according to claim 1 wherein said first and second ground conductors are resistively coupled together in said connection region under said integrated circuit.

3. A circuit structure according to claim 1 wherein the coupling between the first and second ground conductors comprises a coupling element connected to and extending between said first and second ground conductors.

4. A circuit structure according to claim 3 wherein said coupling element comprises a planar resistor mounted on said substrate in said connection region for coupling said first and second ground conductors together.