The signal received by a radio frequency (RF) receiver is often accompanied by some blockers and interferers, which could be from in-band or out-of-band frequencies. Normally, they are with very large signal strength. As a result, they may easily jam and saturate the receiver. To alleviate their effect, one traditional solution is to utilize current-mode direct conversion. Another solution is to employ mixer-first receiver architecture. Although the current-mode and mixer-first architectures have certain tolerance for the blockers and interferers, they can still be saturated, especially with large blocker strength.
This technology offer is an integrated circuit (IC) design of a novel true-current-mode receiver architecture, that can be used to alleviate the receiver saturation problem. The receiver start with a specially designed matching network. The matching networks have two options. Option-1 consists of R-L-C parallel paths, and option-2 is a passive 90° hybrid coupler. Both create “virtual ground” directly at the RF node, thus inducing voltage attenuation rather than voltage amplification at the RF node. This configuration improves the large-signal linearity greatly. Meanwhile, the noise of the matching resistor can be totally cancelled. Moreover, the local oscillator (LO) leakage to the RF port is greatly reduced.
This technology offer is applicable to all mainstream communication systems, including, but not limited to, sub-6 GHz, 5G and 6G receivers. They are also applicable to surface acoustic wave (SAW)-less and full-duplex applications.
The receiver starts with a specially designed matching network. The matching network has two options. Option-1 consists of R-L-C parallel paths, and option-2 is a passive 90° hybrid coupler. Both create “virtual ground” directly at the RF node, thus inducing voltage attenuation rather than voltage amplification at the RF node. This configuration improves the small-signal and large-signal linearity greatly, which results in good Input Third Order Intercept Point, IIP3 (>10 dBm) and out-of-band 1 dB Compression Point, P1dB.
Meanwhile, a noise-cancellation technique is embedded, which cancels the noise of the matching resistor completely. Moreover, compared to conventional mixer-first receivers, the LO leakage of the proposed receiver is greatly reduced with a low RF input impedance. The low local oscillator (LO) leakage makes them more suitable for commercial application.
This receiver architecture is suitable for use in receivers and transceivers in the following applications:
The technology owner is interested to out-license this IC design, e.g., to fabless IC design companies.