Dual conversion transmitter with single local oscillator

• US 8,385,855 B2
• Filed: 11/06/2009
• Issued: 02/26/2013
• Est. Priority Date: 11/07/2008
• Status: Active Grant

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Lorg, Shawn M., Buer, Kenneth V.
• Primary Examiner(s): TRAN, PABLO N
• Application Number:
  US12/614,293
• Publication Number:
  US 20100117693A1
• Time in Patent Office: 1,208 Days
• Field of Search: 455/118, 455/91, 455/112, 455/113, 455/115.1, 455/313, 455/316, 455/318, 455/323, 455101-103, 455/293, 455/258
• US Class Current: 455/118
• CPC Class Codes: H03D 7/163 the local oscillations of at least two of the frequency changers being derived from a single oscillator

Abstract

The present disclosure relates to systems, devices and methods related to transmitters, and/or transceivers having a single, tunable oscillator in a dual conversion architecture. In various exemplary embodiments, this transmitter may include: a first mixer configured to receive a first oscillator signal from the single oscillator; a filter configured to band pass filter the converted signal and output a filtered signal; and a second mixer in communication with the filter, configured to receive the filtered signal. This dual conversion transmitter may be configured to receive a communication signal from an input to the transmitter and to output a converted signal based on the first oscillator signal and the communication signal. The second mixer may be configured to receive a scaled version of the first oscillator signal and to output a desired frequency output signal based on the scaled version of the first oscillator signal and the filtered signal.

Claims

1. A dual conversion transmitter, wherein the transmitter is configured to divide a first oscillator signal into a second oscillator signal and a third oscillator signal, wherein the transmitter is configured to perform frequency scaling such that the second and third oscillator signals have different frequencies from each other, the transmitter further comprising:

a first mixer, wherein the first mixer is configured to utilize the second oscillator signal to facilitate frequency conversion; and

a second mixer, wherein the second mixer is configured to utilize the third oscillator signal to facilitate frequency conversion; and

a filter configured to filter the output of the first mixer and to provide the output of the filter to the input of the second mixer;

wherein the transmit frequency conversion is the result of one of;

(i) the sum of an intermediate frequency (“

IF”

) transmit signal frequency and the third oscillator signal frequency, and (ii) the difference of the IF transmit signal frequency and the third oscillator signal frequency.

2. The dual conversion transmitter of claim 1, the transmitter further comprising a first multiplier configured to scale the frequency of the third oscillator signal such that the second and third oscillator signals have different frequencies from each other.

3. The dual conversion transmitter of claim 1, the transmitter further comprising a sub-harmonic mixer configured to scale the frequency of the third oscillator signal such that the second and third oscillator signals have different frequencies from each other.

4. The dual conversion transmitter of claim 1, wherein the dual conversion transmitter expands the intermediate frequency bandwidth with each subsequent conversion.