Device for Noise Reduction

• US 20080170647A1
• Filed: 07/05/2005
• Published: 07/17/2008
• Est. Priority Date: 07/08/2004
• Status: Abandoned Application

• Current Assignee: Andrew LLC (CommScope Holding Company, Inc.)
• Original Assignee: Andrew Corporation (CommScope Holding Company, Inc.)
• Inventors: Hermansson, Bo, Johansson, Mathias
• Application Number:
  US11/571,621
• Publication Number:
  US 20080170647A1
• Time in Patent Office: Days
• US Class Current: 375/346
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
• CPC Class Codes: H04B 1/707 using direct sequence modulation

Abstract

Device for reducing noise in a radio receiver, which radio receiver comprises a transformer (30) having a reference voltage input (20), a radio signal input at a first transformer side, and a radio signal output at a second transformer side, an A/D converter (40) being connected to said second transformer side, wherein a first bandpass filter (50) is connected between said second transformer side and said A/D converter.

Claims

1. Device for reducing noise in a radio receiver, which radio receiver comprises a transformer having a reference voltage input, a radio signal input at a first transformer side, and a radio signal output at a second transformer side, an A/D converter being connected to said second transformer side, wherein a first bandpass filter is connected between said second transformer side and said A/D converter.

2. The device as recited in claim 1, wherein a second bandpass filter is connected to said first transformer side for suppressing unwanted Nyquist zones from a received radio signal before said transformer.

3. The device as recited in claim 1, wherein said first bandpass filter is devised to suppress common mode noise.

4. The device as recited in claim 1, wherein said first bandpass filter is devised to suppress differential mode noise.

5. The device as recited in any claim 1, wherein said receiver is devised to convert a frequency of an input radio signal to a fixed intermediate frequency, and said A/D converter has a sampling frequency which is less than half said intermediate frequency, wherein said first bandpass filter has a bandwidth which is less than half said intermediate frequency.

6. The device as recited in claim 1, wherein said second transformer side is connected by two leads to said A/D converter, wherein said first bandpass filter includes a capacitive connection between said two leads.

7. The device as recited in claim 6, wherein said first bandpass filter includes an inductive connection between said two leads.

8. The device as recited in claim 6, wherein said first bandpass filter includes a resistive load on each of said two leads.

9. The device as recited in claims 6, wherein said first bandpass filter includes a capacitive connection from ground to each of said two leads.