Multi band pass filters

• US 7,468,642 B2
• Filed: 12/12/2006
• Issued: 12/23/2008
• Est. Priority Date: 12/12/2006
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Mina, Essam, Bavisi, Amit
• Primary Examiner(s): CHO, JAMES HYONCHOL
• Application Number:
  US11/609,413
• Publication Number:
  US 20080136560A1
• Time in Patent Office: 742 Days
• Field of Search: 333/168, 333175-176, 333/32, 333/202
• US Class Current: 333/168
• CPC Class Codes: H03H 2210/015 Quality factor or bandwidth
• CPC Class Codes: H03H 2250/00 Indexing scheme relating to dual- or multi-band filters
• CPC Class Codes: H03H 7/0115 comprising only inductors and capacitors H03H7/075, H03H7/09, H03H7/12, H03H7/13 take precedence
• CPC Class Codes: H03H 7/0161 Bandpass filters H03H7/12 takes precedence
• CPC Class Codes: H03H 7/175 Series LC in series path H03H7/1783 takes precedence
• CPC Class Codes: H03H 7/1766 Parallel LC in series path H03H7/1783 takes precedence
• CPC Class Codes: H03H 7/1783 Combined LC in series path
• CPC Class Codes: H03H 7/1791 Combined LC in shunt or branch path
• CPC Class Codes: H03H 7/38 Impedance-matching networks

Abstract

A multi-band band pass filter, including: first and second multi-order asynchronous resonators connected to each other by a coupling resonator and connected to respective first and second matching resonators, the first matching resonator connected to a signal-in terminal and second matching resonator connected to a signal-out terminal respectively; a first reference resonator connected between the signal-in terminal and a reference-in terminal and a second reference resonator connected between the signal-out terminal and a reference-out terminal, the first multi-order asynchronous resonator connected between the first matching resonator and the coupling resonator to the first reference terminal and the second multi-order asynchronous resonator connected between the second matching resonator and the coupling resonator to the reference-out terminal, the reference-in terminal connected to the reference-out terminal; and a feedback resonator connected between the signal-in terminal and the signal-out terminal.

Claims

1. A multi-band band pass filter, comprising:

first and second multi-order asynchronous resonators connected to each other by a coupling resonator and connected to respective first and second matching resonators, said first matching resonator connected to a signal-in terminal and second matching resonator connected to a signal-out terminal respectively;

a first reference resonator connected between said signal-in terminal and a reference-in terminal and a second reference resonator connected between said signal-out terminal and a reference-out terminal, said first multi-order asynchronous resonator connected between said first matching resonator and said coupling resonator to said first reference terminal and said second multi-order asynchronous resonator connected between said second matching resonator and said coupling resonator to said reference-out terminal, said reference-in terminal connected to said reference-out terminal; and

a feedback resonator connected between said signal-in terminal and said signal-out terminal.

2. The multi-band band pass filter of claim 1, wherein said first multi-order resonator comprises n second order resonators connected in series each having a different resonant frequency and said second multi-order resonator comprises n second order resonators connected in series each having a different resonant frequency, wherein n is a positive integer of 2 or more.

3. The multi-band band pass filter of claim 2, wherein said first and second multi-order resonators are duplicates of each other, said first and second reference resonators are duplicates of each other, and said first and second matching resonators are duplicates of each other.

4. The multi-band band pass filter of claim 1, wherein said first multi-order resonator comprises two second-order resonators connected in series each having a different resonant frequency and said second multi-order resonator comprises two second-order resonators connected in series each having a different resonant frequency, wherein said first and second multi-order resonators are duplicates of each other.

5. The multi-band band pass filter of claim 1, wherein said first and second matching resonators each include a fixed capacitor and said first and second reference resonators each include a fixed capacitor.

6. The multi-band band pass filter of claim 1, wherein said first and second matching resonators each include a variable capacitor and said first and second reference resonators each include a fixed capacitor.

7. The multi-band band pass filter of claim 1, wherein said first and second matching resonators each include a fixed capacitor and said first and second reference resonators each include a variable capacitor.

8. The multi-band band pass filter of claim 1, wherein said first and second matching resonators each include a variable capacitor and said first and second reference resonators each include a variable capacitor.