A linearized and low noise CMOS mixer with B‐type amplifier‐based sub‐harmonic balun

Summary This research reports the development of an RF sensor integrated circuit (IC) chip capable of tracking the directionality of RF remote emissions. The IC design uses an angle‐of‐arrival algorithm, and it is designed for the 180 nm CMOS technology and applicable to other technologies, also. The sensor chip requires two pairs of antennas aligned and placed at distance s for detection of azimuthal and polar angles of the RF incident wave. The circuit consists of custom designed low‐noise amplifiers (LNAs) at the front end, with a novel design of double‐balanced Gilbert cell mixers (GCMs). This amplifies and mixes the signals from the antennas and converts the phase difference Δφ into an equivalent output voltage map suitable for an 18‐bit analog to digital converter. Systematic optimization techniques were developed to maximize the third‐order intercept point and suppress flicker noise for the LNAs and GCMs, resulting in improved sensing accuracy. The overall system‐level evaluation results showed state‐of‐art angle‐of‐arrival sensing capability with an upper limit error of 3.447°.

Section: System Descriptionmentioning

confidence: 99%

“…The first and second signal terms in (10) cancel each other out at the operating frequency f c , and the real term (g m /c gs )L S is matched to the 50Ω antenna. The buffer stage M4 is designed for 50Ω output impedance matching.…”

Section: Circuit Topology and Optimizationmentioning

confidence: 99%

Design and optimization of a CMOS IC novel RF tracking sensor

Chung

Iliadis

2021

“…[11], and the active subharmonic balun in ref. [12]. Most of the baluns are basically focused more on the in‐band operation.…”

Section: Introductionmentioning

confidence: 99%

A lumped‐element balun design with multi‐interference suppression for push–pull power amplifier

Xiang

Qin

et al. 2022

In this article, a lumped-element balun with multi-interference suppression is implemented and presented. Originated from the conventional lattice LC balun, the balun combining two Π-networks is expended to four new topologies. By constructing frequency traps and out-of-phase combining pathways, the new topologies can realize two-or three-interference suppression while maintaining well-matched input/output impedances. The concept is studied theoretically in both even and odd mode circuits, and analytical design equations are also derived. Based on the design theory, four interference suppression balun topologies are proposed for push-pull power amplifiers. To verify the design concept, two of the four topologies working at 1 GHz are prototyped and measured. The measured results agree well with the analysis and simulation results. The two baluns both achieve good performance with low insertion loss better than À3.9 dB, low return loss less than À13.6 dB, good interference suppression more than 24.7 dB, and small phase unbalance less than 0.8 . Furthermore, the proposed balun is used in a gallium nitride push-pull power amplifier to validate the 2nd and 3rd harmonic suppression. The amplifier works at 1 GHz with a typical gain of 16.7 dB. At least À45 dBc interference suppression, 52.6% power-added efficiency, and 34.6 dBm P1dB output power are obtained.

A 24–30‐GHz Modified Gilbert‐Cell Downconverter With High Linearity and Isolation

Fejzullahu,

Alper Ozkan,

Bilgin

et al. 2024

This paper introduces a downconverter mixer employing a modified double‐balanced Gilbert‐cell topology, designed using IHP's 0.13‐m SiGe BiCMOS technology. Distinct from the conventional topology, a resonator was employed at the emitter of the transconductance stage, which enables the utilization of transconductance stage as an active balun, allowing for direct feeding of the single‐ended input without sacrificing the advantageous of the double‐balanced topology. The integration of the resonator reduces the amplitude and phase errors within the active balun segment, thereby enhancing port‐to‐port isolation. The area occupied by the resonator is approximately 1.7 times smaller than that of an RF transformer balun typically employed in conventional double‐balanced topologies. The LO and IF differential signals are converted to single‐ended ones through transformer baluns for measurement purposes. The frequencies of operation for RF, LO, and IF are 24–30, 18–24, and 6 GHz, respectively. The conversion loss is 7.7 dB at 26 GHz, with port‐to‐port isolations exceeding 35 dB. The input 1‐dB compression point is 5.7 dBm, while the circuit consumes 65‐mW power from a 3.3‐V voltage supply. Excluding the pads, the active area of the design spans 1 mm2.