Mixer Circuit with Bypass and Mixing Modes having Constant Even Order Generation and Method of Operation

A mixer circuit configured to operate in a bypass or mixing mode, the mixer circuit comprising:

• a mixer core, which comprises:
• a first switch having an input, a first output, and a second output;
• and
• a second switch having an input, a first output, and a second output;
• and
• a mode select circuit coupled to the mixer core, the mode select circuit comprising:
• first switching means for coupling the first and second outputs of the first switch to either (i) a common potential node or (ii) opposite polarity nodes;
• and
• second switching means for coupling the first and second outputs of the second switch to either (i) a common potential node or (ii) opposite polarity nodes.

A common oscillator, multiple mixer system, comprising:

• an oscillator configured to output a reference signal operating at an reference frequency;
• and
• a plurality of mixer circuits, each mixer circuit coupled to receive the reference signal and each mixer circuit comprising:
• a mixer core, further comprising:
• a first switch having an input switchable between a first output and a second output;
• and
• a second switch having an input switchable between a first output and a second output;
• and
• a mode select circuit coupled to the mixer core, the mode select circuit comprising:
• a third switch having an input coupled to second output of the first switch, the input switchable between a first output coupled to the first output of the first switch, and a second output coupled to the second output of the second switch;
• and
• a fourth switch having an input coupled to the first output of the second switch, the input switchable between a first output coupled to the first output of the first switch, and a second output coupled to the second output of the second switch.

In a system which receives a first signal operating at a first frequency, a method for selectively outputting either the first signal operating at the first frequency, or a signal operating at a frequency defined by the mixing product of the first frequency and a second frequency, the method comprising:

• supplying the first signal to at least one of two input switches, wherein each of the two input switches has an input switchable to either a first output or a second output;
• for each of the first and second switches, switching the input terminal between the first and second outputs at a second frequency;
• and
• connecting the first and second outputs of each of the first and second switches to either (i) a common potential node to output a signal at the first frequency, or (ii) opposite polarity nodes to output a signal at a frequency defined by a mixing product of the first and second frequencies.

In a system which receives a first signal operating at a first frequency, a method for selectively output either the first signal operating at the first frequency, or a signal operating at a frequency defined by a mixing product of the first frequency and a second frequency, the method comprising:

• supplying the first signal at the first frequency to the signal input port of a mixer;
• supplying a second signal at the second frequency to a local oscillator input port of the mixer;
• selectively outputting from an output-port of the mixer either (i) the first signal operating at the first frequency, or (ii) a signal operating at a frequency defined by a mixing product of the first frequency and the second frequency;
• and
• outputting from a port of the mixer a signal at a harmonic frequency of the second frequency at a signal level which is substantially independent of the signals (i) or (ii).