Apparatus and method for down-converting electromagnetic signals by controlled charging and discharging of a capacitor

• US 8,295,800 B2
• Filed: 09/07/2010
• Issued: 10/23/2012
• Est. Priority Date: 04/14/2000
• Status: Expired due to Fees

• Current Assignee: ParkerVision, Inc.
• Original Assignee: ParkerVision, Inc.
• Inventors: Sorrells, David F., Bultman, Michael J., Cook, Robert W., Looke, Richard C., Moses, Charley D. Jr., Rawlins, Gregory S., Rawlins, Michael W.
• Primary Examiner(s): Tran, Pablo
• Application Number:
  US12/876,356
• Publication Number:
  US 20110059715A1
• Time in Patent Office: 777 Days
• Field of Search: 455/313, 455/323, 455/334, 455/318, 455/316, 455/319, 455/325, 455/333, 455/339, 455340-341, 455/130, 455/197.2, 455/203, 455/262, 455/265, 455/284, 455/287, 455/326, 327356-360
• US Class Current: 455/313
• CPC Class Codes: H03D 7/00 Transference of modulation from one carrier to another, e.g. frequency-changing H03D9/00, H03D11/00 take precedence; dielectric amplifiers, magnetic amplifiers, parametric amplifiers used as a frequency-changers H03F
• CPC Class Codes: H04B 1/16 Circuits

Abstract

Methods, systems, and apparatuses for down-converting and up-converting an electromagnetic signal. In embodiments, the invention operates by receiving an electromagnetic signal and recursively operating on approximate half cycles of a carrier signal. The recursive operations can be performed at a sub-harmonic rate of the carrier signal. The invention accumulates the results of the recursive operations and uses the accumulated results to form a down-converted signal. In embodiments, up-conversion is accomplished by controlling a switch with an oscillating signal, the frequency of the oscillating signal being selected as a sub-harmonic of the desired output frequency. When the invention is being used in the frequency modulation or phase modulation implementations, the oscillating signal is modulated by an information signal before it causes the switch to gate a bias signal. The output of the switch is filtered, and the desired harmonic is output.

Claims

1. A method for down-converting an electromagnetic signal, comprising:

(1) receiving an RF information signal;

(2) electrically coupling the RF information signal to a capacitor according to a control signal operating at an aliasing rate selected so that energy of the RF information signal is sampled and applied to the capacitor at a frequency that is equal to or less than twice the frequency of the RF information signal; and

(3) controlling a charging and discharging cycle of the capacitor using the control signal to control a switching device electrically coupled to the capacitor so that the energy transferred from the RF information signal to the capacitor directly forms a down-converted signal.

2. The method according to claim 1, further comprising amplifying said down-converted signal.

3. The method according to claim 1, further comprising generating a control signal to control said switching device.

4. The method according to claim 3, wherein said control signal comprises a train of pulses, each pulse having a first and a second edge.

5. The method according to claim 1, wherein said switching device closes on the first edge of each pulse.

6. The method according to claim 5, wherein said switching device opens on the second edge of each pulse.

7. The method according to claim 1, wherein energy from said RF information signal is stored in said capacitor when said switching device is closed.