Method and system for frequency up-conversion

• US 20030022640A1
• Filed: 03/04/2002
• Published: 01/30/2003
• Est. Priority Date: 08/23/1999
• Status: Active Grant

• Current Assignee: ParkerVision, Inc.
• Original Assignee: ParkerVision, Inc.
• Inventors: Cook, Robert W., Bultman, Michael J., Sorrells, David F., Moses, Charley D. Jr., Looke, Richard C.
• Granted Patent: US 7,236,754 B2
• Time in Patent Office: Days
• US Class Current: 455/118
• CPC Class Codes: H03C 1/36 by means of semiconductor device having at least three electrodes H03C1/34, H03C1/50, H03C1/52, H03C1/62 take precedence
• CPC Class Codes: H03C 3/38 by converting amplitude modulation to angle modulation
• 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: H03D 7/125 with field effect transistors
• CPC Class Codes: H04B 2001/0491 with frequency synthesizers, frequency converters or modulators

Abstract

A method and system is described wherein a signal with a lower frequency is up-converted to a higher frequency. In one embodiment, the higher frequency signal is used as a stable frequency and phase reference. In another embodiment, the invention is used as a transmitter. The 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 as a frequency or phase reference, the oscillating signal is not modulated, and controls a switch that is connected to a bias signal. When the invention is being used in the frequency modulation (FM) or phase modulation (PM) implementations, the oscillating signal is modulated by an information signal before it causes the switch to gate the bias signal. In the amplitude modulation implementation (AM), the oscillating signal is not modulated, but rather causes the switch to gate a reference signal that is substantially equal to or proportional to the information signal. In the FM and PM implementations, the signal that is output from the switch is modulated substantially the same as the modulated oscillating signal. In the AM implementation, the signal that is output from the switch has an amplitude that is a function of the information signal. In both embodiments, the output of the switch is filtered, and the desired harmonic is output.

Claims

1. A method for up-converting an electromagnetic signal, the electromagnetic signal having a first frequency, comprising:

(1) gating a bias signal at a rate proportional to the first frequency of the electromagnetic signal to generate a harmonically rich signal having a plurality of harmonics; and

(2) selecting at least one of said plurality of harmonics as a desired signal having at least a second frequency.

2. The method of claim 1, further comprising:

(3) shaping the electromagnetic signal, resulting in a shaped signal, said shaped signal being a substantially rectangular waveform having a third frequency, said third frequency being proportional to the first frequency, said substantially rectangular waveform further having a period that is an inverse of said third frequency, a pulse width, and a pulse ratio, said pulse ratio being a ratio of said pulse width to said period; and

wherein

said bias signal is gated in step (1) at a rate proportional to said third frequency.

3. The method of claim 2, wherein said pulse ratio is substantially equal to or less than 0.5.

4. The method of claim 1, wherein the electromagnetic signal is modulated.

5. The method of claim 1, wherein said bias signal is related to an information signal.

6. The method of claim 1, wherein said second frequency is higher than the first frequency.