A polarimetric millimeter-wave radar imaging technique is proposed to remotely detect, localize, and wirelessly read a novel additively manufactured passive sensor composed of a microfluidic channel filled with liquid metal Galinstan. Very high variation of the radar-cross section of the sensor to small variations of the level of Galinstan in the channel is obtained. The measured radar echo level of the sensor varies by 4.5 dB when the level of Galinstan changes by 1 mm.

Harmonic radar systems have been implemented for applications where distinction between specific targets and surrounding clutter is required. However, the doubled frequencies conventionally used in harmonic radar systems are not licensed for automotive applications. Instead of harmonic, the relation between the two bands necessitates what we propose to call inharmonic radar. Therefore, an innovative frequency conversion approach is required. The presented approach has an active tag based on a novel 1.75 times fractional frequency multiplier.

Heart rate variability (HRV) analysis using Doppler radar is a promising method for noninvasive health and stress assessment. However, the respiration signal harmonic content typically limits HRV parameter estimation accuracy. While several harmonic reduction techniques have been used to improve the average HR estimation accuracy, achieving high beat-to-beat interval accuracy is still challenging. This article demonstrates that arctangent demodulation with wavelet-based signal processing enhanced with template matching is effective to estimate HRV parameters.

Considering the imperfect communication channel state information (CSI), this paper investigated a robust joint design of transmit waveform and receive filter for the dual-functional radar-communication (DFRC) system using a multi-input-multi-output (MIMO) platform. In this study, the output signal-to-interference-plus-noise ratio (SINR) of the radar was used as the cost function, while formulating communication constructive interference constraints under imperfect estimation of communication CSI. To solve the complicated non-convex problem, two efficient algorithms in both Euclidean and Riemannian spaces were developed. 

In this paper, an architecture to generate and distribute multiband frequency-synchronized sources is studied through an experimental system for simultaneous transmission at 100 and 112.5 GHz. An electrooptic frequency comb was generated OFF-site and distributed to multiple locations using optical fibers of various lengths and total chromatic dispersion. The effect of the dispersion is studied and demonstrated experimentally. At each site, the optical comb is converted to the equivalent electrical comb using a photodiode without prior optical filtering.