Method and system for down-converting an Electromagnetic signal, transforms for same, and Aperture relationships

• US 20090203345A1
• Filed: 05/02/2008
• Published: 08/13/2009
• Est. Priority Date: 10/21/1998
• Status: Active Grant

• Current Assignee: ParkerVision, Inc.
• Original Assignee: ParkerVision, Inc.
• Inventors: Cook, Robert W., Rawlins, Gregory S., Bultman, Michael J., Sorrells, David F., Moses, Charley D. JR., Looke, Richard C., Rawlins, Michael W.
• Granted Patent: US 7,693,502 B2
• Time in Patent Office: Days
• US Class Current: 455/313
• CPC Class Codes: H03C 1/62 Modulators in which amplitude of carrier component in output is dependent upon strength of modulating signal, e.g. no carrier output when no modulating signal is present H03C1/28 - H03C1/34, H03C1/46, H03C1/48 take precedence
• 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 7/1441 using field-effect transistors H03D7/145 takes precedence
• CPC Class Codes: H03D 7/1475 Subharmonic mixer arrangements
• CPC Class Codes: H04B 1/0025 using a sampling rate lower than twice the highest frequency component of the sampled signal for demodulation of angle-modulated signals H03D3/006
• CPC Class Codes: H04B 1/16 Circuits
• CPC Class Codes: H04B 1/28 the receiver comprising at least one semiconductor device having three or more electrodes
• CPC Class Codes: H04B 7/12 Frequency diversity
• CPC Class Codes: H04L 25/08 Modifications for reducing interference; Modifications for reducing effects due to line faults ; Receiver end arrangements for detecting or overcoming line faults
• CPC Class Codes: H04L 27/00 Modulated-carrier systems
• CPC Class Codes: H04L 27/06 Demodulator circuits; Receiver circuits
• CPC Class Codes: H04L 27/12 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04L 27/14 Demodulator circuits; Receiver circuits
• CPC Class Codes: H04L 27/148 using filters, including PLL-type filters
• CPC Class Codes: H04L 27/156 with demodulation using temporal properties of the received signal, e.g. detecting pulse width
• CPC Class Codes: H04L 27/2672 Frequency domain
• CPC Class Codes: H04L 27/3881 using sampling and digital processing, not including digital systems which imitate heterodyne or homodyne demodulation

Abstract

Methods, systems, and apparatuses, and combinations and sub-combinations thereof, for down-converting an electromagnetic (EM) signal are described herein. Briefly stated, in embodiments the invention operates by receiving an EM signal and recursively operating on approximate half cycles (½, 1½, 2½, etc.) of the 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 an embodiment, the EM signal is down-converted to an intermediate frequency (IF) signal. In another embodiment, the EM signal is down-converted to a baseband information signal. In another embodiment, the EM signal is a frequency modulated (FM) signal, which is down-converted to a non-FM signal, such as a phase modulated (PM) signal or an amplitude modulated (AM) signal.

Claims

1-74. -74. (canceled)

75. An apparatus for down-converting an electromagnetic signal, comprising:

a multiplying module to down-convert an initially-received carrier signal;

a switching module, coupled to the multiplying module, to gate an output of the multiplying module; and

an integrating module, coupled to the switching module, to integrate the gated output of the multiplying module.

76. The apparatus of claim 75, further comprising:

a filter, coupled to the integrating module, to reconstruct an accumulated output from the integrating module into a down-converted carrier signal.

77. The apparatus of claim 76, wherein the filter is at least one of a reconstruction filter and an interpolation filter.

78. The apparatus of claim 76, wherein the multiplying module, switching module, and integrating module are configured to operate simultaneously with each other at a sub-harmonic frequency relative to the carrier signal.

79. The apparatus of claim 75, wherein the multiplying module comprises a first input port to receive the carrier signal and a second input port to receive a signal representative of the carrier signal.

80. The apparatus of claim 79, wherein the multiplying module is configured to convolve the representative signal with an approximate half cycle of the carrier signal in order to acquire energy from the carrier signal.

81. The apparatus of claim 75, wherein the switching module comprises a transistor.

82. The apparatus of claim 81, wherein the transistor comprises a control terminal coupled to a control signal, the control signal representative of a windowing function with a predetermined aperture length.

83. The apparatus of claim 82, wherein the predetermined aperture length is approximately equal to a half cycle of the carrier signal.

84. The apparatus of claim 75, wherein the integrating module comprises an energy storage device to store a portion of energy contained in an approximate half cycle of the carrier signal.

85. The apparatus of claim 84, wherein the energy storage device comprises a capacitive storage device.