Mixer with high second-order and third-order intercept point
Embodiments of apparatuses, systems and methods relating to a mixer having high second- and third-order intercept points are disclosed. Other embodiments may be described and claimed.
1. A mixer comprising:
first and second transistors, wherein the first transistor has a gate configured to receive a local oscillator (LO) drive signal, a source coupled with ground, and a drain, and the second transistor has a gate configured to receive the LO drive signal, a source coupled with ground, and a drain;
a radio-frequency (RF) balun having primary and secondary windings, with the primary windings coupled with an RF signal node, a first secondary winding of the secondary windings coupled with a first intermediate frequency (IF) signal node, and a second secondary winding of the secondary windings coupled with a second IF signal node, wherein the first and second IF signal nodes are configured to provide a differential IF signal interface;
a first capacitor coupled with the first secondary winding and configured to provide a ground return at a first RF grounding port for an RF signal; and
a second capacitor coupled with the second secondary winding and configured to provide a ground return at a second RF grounding port for the RF signal.
2. The mixer of claim 1 , further comprising:
an amplifier configured to amplify a LO signal,
wherein the LO drive signal is based on the amplified LO signal.
3. The mixer of claim 2 , further comprising:
a capacitor coupled with the amplifier and the first and second transistors and configured to provide the LO drive signal based on the amplified LO signal.
4. The mixer of claim 1 , wherein the first secondary winding is coupled with a drain of the first transistor and the second secondary winding is coupled with a drain of the second transistor.
5. The mixer of claim 1 , further comprising:
a diplexer including the RF balun, the first capacitor, and the second capacitor and configured to diplex the RF signal and an IF signal.
6. The mixer of claim 5 , further comprising:
a plurality of capacitors to facilitate tuning RF balun at desired frequencies, the plurality of capacitors including a third capacitor coupled in parallel with the first secondary winding, a fourth capacitor coupled in parallel with the second secondary winding, and a fifth capacitor coupled in parallel with the first and the second primary windings.
7. The mixer of claim 1 , wherein the RF signal is a single-ended signal.
8. The mixer of claim 1 , further comprising:
a first inductor-capacitor segment coupled with the first RF grounding port and ground and configured to resonate at the RF signal to further ground the RF signal; and
a second inductor-capacitor segment coupled with the second RF grounding port and ground and configured to resonate at the RF signal to further ground the RF signal.
9. The mixer of claim 1 , wherein the mixer is a monolithic mixer with the first and second transistors and the RF balun integrated in a single integrated circuit.
10. The mixer of claim 1 , wherein the mixer has a second-order intercept point of greater than approximately 60 dBm and a third-order intercept point greater than approximately 30 dBm.
11. The mixer of claim 1 , wherein the RF balun is a balun that includes a first concentric structure coupled with a second concentric structure.
12. The mixer of claim 11 , further comprising:
a connection to couple the first and second concentric structures at interior portions of the first and second concentric structures.
13. The mixer of claim 1 , including a first inductor coupled with the first IF signal node and a second inductor coupled with the second IF signal node, wherein the first and second inductors are configured to increase an RF-to-IF and LO-to-IF signal isolation.
14. A receiver comprising:
a first channel having a first mixer configured to receive a first single-ended radio frequency (RF) signal and an amplified local oscillator (LO) signal and to generate a first differential intermediate frequency (IF) signal, the first mixer including an RF balun with primary windings coupled with a node to receive the first single-ended RF signal and secondary windings coupled with IF nodes to output the first differential IF signal, the secondary windings further coupled with a pair of transistors configured to receive an LO drive signal that is based on the LO signal, wherein the first mixer comprises a first RF grounding port coupled with a first secondary winding and a second RF grounding port coupled with a second secondary winding; and
a second channel having a second mixer configured to receive a second single-ended RF signal and the LO signal and to generate a second differential IF signal.
15. The receiver of claim 14 , further comprising:
a mixer block, having the first and second mixers, that is monolithically integrated into a single integrated circuit.
16. The receiver of claim 14 , wherein the second mixer comprises:
an RF balun with primary windings coupled with a node to receive the second single-ended RF signal and secondary windings coupled with IF nodes to output the second differential IF signal, the secondary windings further coupled with drains from a pair of transistors configured to receive an LO drive signal that is based on the LO signal.
17. The receiver of claim 14 , wherein the first channel further includes an amplifier input coupled with a local oscillator and output coupled with capacitor, with the capacitor coupled to the gates of the pair of transistors to receive the LO drive signal, wherein the LO drive signal is based on the amplified LO signal.
18. The receiver of claim 14 , wherein the mixer further comprises:
a first capacitor coupled with ground and the first RF grounding port; and
a second capacitor coupled with ground and the second RF grounding port.