Backscatter receiver maintaining sensitivity with varying power levels

• US 20060094392A1
• Filed: 11/01/2004
• Published: 05/04/2006
• Est. Priority Date: 11/01/2004
• Status: Active Grant

• Current Assignee: Amtech Systems LLC (Roper Technologies, Inc.)
• Original Assignee: TC License Limited
• Inventors: Youn, Tai Won
• Granted Patent: US 7,477,887 B2
• Time in Patent Office: Days
• US Class Current: 455/324
• CPC Class Codes: H03G 3/3052 in bandpass amplifiers (H.F. or I.F.) or in frequency-changers used in a (super)heterodyne receiver H03G3/32, H03G3/34 take precedence

Abstract

A method and apparatus for maintaining sensitivity of a homodyne receiver over varying transmitter power levels is disclosed. The method includes adjusting output power levels of a transmitter driver. A bias supply voltage to the transmitter driver may be adjusted to adjust the output power levels. A control voltage to the transmitter driver may be adjusted to adjust the output power levels of the transmitter driver. A homodyne radio frequency tag reader may include the method.

Claims

1. A method for maintaining sensitivity of a homodyne receiver over varying transmitter power levels comprising adjusting output power levels of an adjustable gain amplifier which forms a part of said homodyne receiver.

2. The method according to claim 1, comprising adjusting a bias supply voltage to the adjustable gain amplifier.

3. The method according to claim 1, comprising adjusting a control voltage to the adjustable gain amplifier.

4. A method for maintaining sensitivity of a homodyne receiver over varying transmitter power levels comprising adjusting output power levels of a transmitter driver which forms a part of said homodyne receiver.

5. The method according to claim 4, comprising adjusting a bias supply voltage to the transmitter driver.

6. The method according to claim 4, comprising adjusting a control voltage to the transmitter driver.

7. A homodyne radio frequency tag reader that maintains sensitivity over varying transmitter power levels by adjusting output power levels of a power amplifier driver which forms a part of said homodyne receiver.

8. The tag reader of claim 7, wherein a bias supply voltage to the power amplifier driver is adjusted.

9. The tag reader of claim 7, wherein a control voltage to the power amplifier driver is adjusted.

10. The tag reader of claim 7, wherein the sensitivity of the power amplifier driver hardly changes from a +32 dBm through +20 dBm of the transmitter power levels, and linearly decreases from +20 dbm through +10 dbm.

11. The tag reader of claim 7, wherein the sensitivity of the power amplifier driver provides approximately a +10 dB advantage for the transmitter power levels of +32 dBm through +10 dBm.