Active inductor

• US 6,737,944 B2
• Filed: 03/15/2001
• Issued: 05/18/2004
• Est. Priority Date: 09/04/2000
• Status: Expired due to Fees

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Technology Corporation (Renesas Electronics Corporation)
• Inventors: Kunikiyo, Tatsuya
• Primary Examiner(s): Pascal, Robert
• Assistant Examiner(s): GLENN, KIMBERLY E
• Application Number:
  US09/805,925
• Publication Number:
  US 20020047760A1
• Time in Patent Office: 1,160 Days
• Field of Search: 333/214, 333/215
• US Class Current: 333/214
• CPC Class Codes: H03H 11/48 simulating reactances

Abstract

A transistor M1 has its drain connected to a source of a transistor M2 through a capacitor Cc₃. A series connection of a resistor R and a capacitor Cc₁ is provided between a source of the transistor M1 and a gate of the transistor M2. The transistor M1 has its gate connected to a drain of the transistor M2 through a capacitor Cc₂. Appropriate dc bias potentials P₁, P₂ and P₃ are provided for the drain of the transistor M2, the gate and the drain of the transistor M1, respectively, so that an active inductor is obtained between the gate and the source of the transistor M2.

Claims

1. An active inductor comprising first and second field effect transistors, each having a source, a gate and a drain, wherein

said drain of said first field effect transistor is connected to said source of said second field effect transistor,

said gate of said first field effect transistor is connected to said drain of said second field effect transistor with no active element interposed therebetween,

said active inductor further comprising a feedback path provided between said source of said first field effect transistor and said gate of said second field effect transistor, wherein

said gate and said source of said second field effect transistor serve as two ports of said active inductor, and

a field effect transistor for feedback provided on said feedback path, having a source connected to said source of said first field effect transistor, a gate and a drain connected to each other and to one of said two ports of said inductor.

2. An active inductor comprising first and second field effect transistors, each having a source, a gate and a drain, wherein

said drain of said first field effect transistor is connected to said source of said second field effect transistor,

said gate of said first field effect transistor is connected to said drain of said second field effect transistor with no active element interposed therebetween,

said active inductor further comprising a feedback path provided between said source of said first field effect transistor and said gate of said second field effect transistor, wherein

said gate and said source of said second field effect transistor serve as two ports of said active inductor, and

further comprising a resistor for feedback provided on said feedback path.

3. An active inductor comprising first and second field effect transistors, each having a source, a gate and a drain, wherein

said drain of said first field effect transistor is connected to said source of said second field effect transistor,

said gate of said first field effect transistor is connected to said drain of said second field effect transistor with no active element interposed therebetween,

said active inductor further comprising a feedback path provided between said source of said first field effect transistor and said gate of said second field effect transistor, wherein

said gate and said source of said second field effect transistor serve as two ports of said active inductor, and

further comprising a second capacitor interposed between said gate of said first field effect transistor and said drain of said second field effect transistor.

4. The active inductor according to claim 3, further comprising a third capacitor interposed between said drain of said first field effect transistor and said gate of said second field effect transistor.

5. The active inductor according to claim 4, further comprising a fourth capacitor provided on said feedback path.

6. The active inductor according to claim 3, further comprising a fourth capacitor provided on said feedback path.