Amplifier circuit for amplifying sinusoid signals

A system comprising:

• an amplifier circuit configured to amplify a plurality of sinusoid signals, wherein the sinusoid signals have a relative phase difference to each other, the amplifier circuit comprising:
• a first sequence of at least three transistor amplifiers, wherein:
• a first terminal of each transistor amplifier of the first sequence is configured to receive one respective signal of the plurality of sinusoid signals;
• and
• a second terminal of each transistor amplifier of the first sequence is connected to
• a current source;
• a second sequence of at least three transistor amplifiers comprising a first transistor amplifier and a last transistor amplifier, wherein:
• a second terminal of each transistor amplifier of the second sequence is connected to a third terminal of one respective transistor amplifier of the first sequence;
• a third terminal of each transistor amplifier of the second sequence is connected to a supply voltage;
• a first terminal of each transistor amplifier of the second sequence is connected to the third terminal of a next transistor amplifier of the second sequence;
• wherein the first terminal of the last transistor amplifier is connected to the third terminal of the first transistor amplifier;
• and
• wherein the first terminals are bases or gates, the second terminals are emitters or sources, and the third terminals are collectors or drains;
• and
• a poly-phase filter circuit configured to output the plurality of sinusoid signals via a plurality of outputs of the poly-phase filter circuit, wherein the sinusoid signals have a relative phase difference to each other, and wherein each first terminal of the transistor amplifiers of the first sequence is connected to a corresponding output of the plurality of outputs of the poly-phase filter circuit.

A mixer comprising:

• a system comprising:
• an amplifier circuit configured to amplify a plurality of sinusoid signals, wherein the sinusoid signals have a relative phase difference to each other, the amplifier circuit comprising:
• a first sequence of at least three transistor amplifiers, wherein:
• a first terminal of each transistor amplifier of the first sequence is configured to receive one respective signal of the plurality of sinusoid signals;
• and
• a second terminal of each transistor amplifier of the first sequence is connected to
• a current source;
• a second sequence of at least three transistor amplifiers comprising a first transistor amplifier and a last transistor amplifier, wherein:
• a second terminal of each transistor amplifier of the second sequence is connected to a third terminal of one respective transistor amplifier of the first sequence;
• wherein
• a third terminal of each transistor amplifier of the second sequence is connected to a supply voltage;
• wherein
• a first terminal of each transistor amplifier of the second sequence is connected to the third terminal of a next transistor amplifier of the second sequence;
• wherein the first terminal of the last transistor amplifier is connected to the third terminal of the first transistor amplifier;
• and
• wherein the first terminals are bases or gates, the second terminals are emitters or sources, and the third terminals are collectors or drains,
• a poly-phase filter circuit configured to output the plurality of sinusoid signals via a plurality of outputs of the poly-phase filter circuit, wherein the sinusoid signals have a relative phase difference to each other, and wherein each first terminal of the transistor amplifiers of the first sequence is connected to a corresponding output of the plurality of outputs of the poly-phase filter circuit;
• and
• a filter.