Transformer-based current-reuse amplifier with embedded IQ generation for compact image rejection architecture in multi-band millimeter-wave 5G communication
According to one embodiment, a transformer-based in-phase and quadrature (IQ) includes a differential balun having a first inductor and a second inductor. The first inductor has a first input terminal and a first output terminal. The second inductor has a second input terminal and a second output terminal. Additionally, the IQ generator circuit includes a third inductor magnetically coupled with the first inductor. The third inductor has a first isolation terminal and a third output terminal. The IQ generator circuit also includes a fourth inductor magnetically coupled with the second inductor. The fourth inductor has a second isolation terminal and a fourth output terminal. The IQ generator circuit additionally includes a first transistor coupled to the first input terminal of the first inductor. Further, the generator circuit includes a second transistor coupled to the second input terminal of the second inductor. The first transistor, the second transistor, the first inductor, and the second inductor form a part of a differential amplifier.
1. A transformer-based in-phase and quadrature (IQ) generator circuit with an integrated amplifier, the IQ generator circuit comprising:
a differential balun comprising a first inductor and a second inductor, the first inductor having a first input terminal and a first output terminal, the second inductor having a second input terminal and a second output terminal;
a third inductor magnetically coupled with the first inductor, the third inductor having a first isolation terminal and a third output terminal;
a first resistor coupled to between the first isolation terminal of the third inductor and a voltage source;
a third resistor coupled between the third output terminal and the voltage source;
a fourth inductor magnetically coupled with the second inductor, the fourth inductor having a second isolation terminal and a fourth output terminal;
a first transistor coupled to the first input terminal of the first inductor; and
a second transistor coupled to the second input terminal of the second inductor, wherein the first transistor, the second transistor, the first inductor, and the second inductor form a part of a differential amplifier.
2. The IQ generator circuit of claim 1 , further comprising:
a second resistor coupled to between the second isolation terminal of the fourth inductor and the voltage source.
3. The IQ generator circuit of claim 2 , further comprising:
a fourth resistor coupled between the fourth output terminal and the voltage source.
4. The IQ generator circuit of claim 3 , wherein the first resistor and the third resistor are configured to have resistance such that an amount of direct current (DC) flowing through the third inductor is below a first predetermined threshold.
5. The IQ generator circuit of claim 3 , wherein the second resistor and the fourth resistor are configured to have resistance such that that an amount of direct current (DC) flowing through the fourth inductor is below a second predetermined threshold.
6. The IQ generator circuit of claim 1 , further comprising:
a fifth resistor coupled between the first output terminal and a voltage source; and
a sixth resistor coupled between the second output terminal and the voltage source.
7. The IQ generator circuit of claim 1 , wherein the first output terminal represents a positive in-phase (I+) output terminal to output an I+ signal, and wherein the second output terminal represents a negative in-phase (I−) output terminal to output an I− signal.
8. The IQ generator circuit of claim 1 , wherein the third output terminal represents a negative quadrature-phase (Q−) output terminal to output a Q− signal, and wherein the fourth output terminal represents a positive quadrature-phase (Q+) output terminal to output a Q+ signal.
9. The IQ generator circuit of claim 1 , wherein inputs of the first and second transistors are configured to receive differential input signals.
10. The IQ generator circuit of claim 1 , further comprising:
a third transistor coupled between the first transistor and the first input terminal; and
a fourth transistor coupled between the second transistor and the second input terminal, wherein the first inductor, the second inductor, the first transistor, the second transistor, the third transistor, and the fourth transistor form a part of a cascode amplifier.