Frequency translation circuit and method of translating

• US 6,144,846 A
• Filed: 12/31/1997
• Issued: 11/07/2000
• Est. Priority Date: 12/31/1997
• Status: Expired due to Term

• Current Assignee: North Star Innovations Inc. (Wi-LAN Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Durec, Jeffrey C.
• Primary Examiner(s): Nguyen, Lee
• Assistant Examiner(s): Ferguson, Keith
• Application Number:
  US09/002,307
• Time in Patent Office: 1,042 Days
• Field of Search: 455/323, 455/326, 455/313, 455/333, 455/112, 455/113, 455/118, 455/110, 455/255, 455/256, 455/260, 455/314, 455/315, 327/356, 327/355, 327/113, 327/116, 327/119
• US Class Current: 455/323
• CPC Class Codes: H03D 2200/0033 Current mirrors
• CPC Class Codes: H03D 7/1433 using bipolar transistors H03D7/145 takes precedence
• CPC Class Codes: H03D 7/1441 using field-effect transistors H03D7/145 takes precedence
• CPC Class Codes: H03D 7/1458 Double balanced arrangements, i.e. where both input signals are differential
• CPC Class Codes: H03D 7/1475 Subharmonic mixer arrangements
• CPC Class Codes: H03D 7/163 the local oscillations of at least two of the frequency changers being derived from a single oscillator
• CPC Class Codes: H03D 7/165 at least two frequency changers being located in different paths, e.g. in two paths with carriers in quadrature combined with amplitude demodulation H03D1/2245, combined with angle demodulation H03D3/007; N-path filters H03H19/002
• CPC Class Codes: H04B 1/28 the receiver comprising at least one semiconductor device having three or more electrodes

Abstract

A frequency translation circuit (10) translates an incoming reference signal (RF_IN) to a lower frequency using a compound mixer circuit (42). The compound mixer circuit (42) has a first mixer circuit (14A) that receives both the incoming reference signal (RF_IN) and a signal generated by a first counter (28A). A second mixer circuit (14X) of the compound mixer circuit (42) receives a signal generated by a second counter (28X) and further translates the signal received from the first mixer circuit (14A) to a lower frequency. Both the first mixer circuit (14A) and the second mixer circuit (14X) generate output signals having a carrier frequency that is lower in frequency by the difference of the two input signals.

Claims

1. A frequency translation circuit, comprising:

a first mixer circuit having a first input coupled for receiving a first signal and a second input coupled for receiving a second signal;

a second mixer circuit having a first input coupled to an output of the first mixer circuit and a second input; and

a counter having a first terminal coupled to the second input of the first mixer circuit and a second terminal coupled to the second input of the second mixer circuit to provide signals at the second inputs of the first and second mixer circuits having frequencies different from one another.

2. The frequency translation circuit of claim 1, further comprising a phase shifter having an input coupled to an output of the counter and an output coupled to the second input of the first mixer circuit.

3. The frequency translation circuit of claim 1, further comprising a phase shifter having an input coupled to an output of the counter and an output coupled to the second input of the second mixer circuit.

4. A compound mixer circuit for translating a frequency, comprising:

a first mixer circuit having first and second input terminals and an output terminal;

a first counter having an input coupled for receiving an input signal;

a first phase shift circuit having an input coupled to an output of the first counter and an output terminal coupled to the second input terminal of the first mixer circuit;

a second mixer circuit having a first input terminal coupled to the output terminal of the first mixer circuit;

a second counter having an input coupled for receiving the input signal; and

a second phase shift circuit having an input coupled to an output of the second counter and an output terminal coupled to a second input terminal of the second mixer circuit.