With the increased concern over contact-transmitted diseases and the rapid growth in the field of telemedicine, it is critical to develop remote diagnostic systems to meet these needs. In this paper, multiple methods of remote vital sign estimation are explored and combined to form a multi-functional remote health monitoring system. Camera-based systems are utilized to estimate patient heart rate, blood pressure, SpO2, and temperature under the assumption of adequate lighting. Similarly, radar-based systems are used as a more robust method to estimate patient heart and respiration rate. These two methods are used simultaneously to capture all of the major vital signs of human subjects. Results show the proposed system can perform with high accuracy in each of its functionalities.

An improved, efficient, Rational Generalized Memory Polynomial (RGMP) inverse model based, digital predistortion (DPD) is presented for high efficiency wide bandwidth envelope tracking (ET) power amplifiers (ETPA) for wideband carrier aggregated (CA) signals. This ET configuration is specifically designed for wideband carrier aggregation (CA) signals that have 500 MHz corrected bandwidth and high peak to average ratio signals. Term selection is performed with Doubly Orthogonal Matching Pursuit (DOMP), an efficient sparse signal processing technique. This algorithm has been implemented for open loop and a batch mode closed loop operation. This model and these techniques reduce the number of inverse model terms significantly, using <40 terms of hundreds, while achieving improved spectral emissions, with computational efficiency, output signal fidelity and improved power efficiency. These algorithms are evaluated on a Gen 3, Xilinx ZCU208 RFSoC, achieving specification compliant performance, enabling future efficient real time closed loop operation. Measurements of a 2CA (PAPR=4.2dB) and 4CA (PAPR=6dB) signal with up to 500 MHz signal bandwidth on a Wolfspeed CG2H40025 GaN device around 3.7 GHz are presented. The 2CA signal, with peak to average ratio (PAPR) of 4.2dB after crest factor reduction achieves Po>41.2dBm, NRMSE <2%, and <-40dBc spectral regrowth with Adagio™ DPD.

An improved modeling strategy that extends the inverse model range of applicability (RoA) is applied in this paper. The Rational Generalized Memory Polynomial (RGMP) inverse model based, digital predistortion (DPD) is utilized on a high efficiency wide bandwidth envelope tracking (ET) power amplifier (ETPA) for wideband carrier aggregated (CA) signals. This ET configuration is specifically designed for a variety of wideband CA signals that have up to 500MHz corrected bandwidth. Term selection is performed with Doubly Orthogonal Matching Pursuit (DOMP) using <40 terms of hundreds, while achieving improved spectral emissions, with computational efficiency, output signal fidelity and improved power efficiency. The bench has a Gen 3, Xilinx ZCU208 RFSOC, for the signal generation and RGMP DPD. We evaluated a variety of 2CA (PAPR=4.2dB) and 4CA (PAPR=6dB) signals with up to 500MHz signal bandwidth on a Wolfspeed CG2H40025 GaN RFPA between 3.4-3.9GHz. With the extended RoA, the specific 4CA signals, with PAPR=6dB with 480MHz bandwidth achieve Po>40dBm, DE>34% and <-35dBc spectral regrowth with RGMP DPD and Adagio™ ET signals.

An efficient, multi-carrier envelope tracking power amplifier system for next generation phased array applications, capable of frequency hopping over 500 MHz of bandwidth on four RF power amplifiers simultaneously from a single FPGA is presented with performance results. The band-limited Adagio envelope shaping technique enables multi-carrier envelope tracking to enhance RF power amplifier efficiency, while novel digital pre-distortion algorithms that generate multi-waveform models were developed to enhance linearity over wide bandwidths. Crest factor reduction algorithms were used to reduce the high PAPR that is a consequence of wide bandwidth multi-carrier signals. To validate the high efficiency and linearity of this parallelized system while frequency hopping, a combination of four different types of waveform signals, each containing two to four carriers spread across 500 MHz of bandwidth and independently frequency hopping, were tested on four separate ETPA elements simultaneously. Each of the four sub-systems demonstrated post digital pre-distortion results for spectral regrowth of better than -35 dBc, drain efficiency better than 35%, gain of 8 dB to 12 dB, and average output powers of 40 dBm to 43 dBm.

A low E-band dual-input two-stage Doherty power amplifier is demonstrated using 40-nm T-gate GaN technology. Power-dependent biasing is used to enhance efficiency, with zero bias current of the auxiliary amplifier in backoff while the same bias is applied to both main and auxiliary amplifier at full power to achieve high output power and efficiency. Using the Ozen lumped-element Doherty combiner design technique, the effects of FET parasitic components are minimized. In on-wafer testing, the fabricated MMIC achieves PAE of 34% at output power of 25 dBm (backoff case) and at 29 dBm (full power case) at 71 GHz.

Remote vital signs monitoring using millimeter-wave (mmWave) sensors has gained lots of attention because of their contactless, portable advantages. However, their received signals are more sensitive to random body motions (RBM) which degrades the accuracy of heart rate (HR) detection. To overcome this challenge, multi-input multi-output (MIMO) configuration can be used to reduce RBM's impact as each channel has different points of view with respect to the subject under test (SUT). Here we propose the use of a Frequency Modulated Continuous Wave (FMCW) radar from Texas Instruments (TI) at 77 GHz to collect data from its 192-channel configuration. Since vital sign information extracted using Arctangent Demodulation (AD) could be corrupted by either RBM or respiratory harmonics, a method is needed to minimize such effects. Hence, we develop an algorithm where a Heartbeat Template (HBT) is extruded based on the Constellation Diagram that shows the Quadrature signals from the target's range profile. The HBT is then used to design an adapted-wavelet for Continuous Wavelet Transform (CWT) to magnify the heartbeat signals. Under circumstances where RBM overwhelms the heartbeat signal that the HBT cannot completely reduce its effects, a spectral-based HR selection method is also developed to estimate the HR. By employing the proposed methods, we have reduced mean-error <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\mu _e}$</tex-math></inline-formula> of HR estimation significantly from 9 bpm to less than 2 bpm.

<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> Simultaneous transmit and receive (STAR) radio architectures are of strong interest as they can double data rates in communication links. To achieve acceptable performance, high power coupled from the transmitter into the receiver must be suppressed at the receiver end. In this regard, a wideband RF front end is required, which will provide high isolation. In addition to the antenna, this designed RF front end board includes a custom-designed RF-SIC filter, multiple power splitters/combiners and baluns to generate a weighted coupled signal at the receiver. This captured signal from the transmitter is used to cancel out the interference from the overall receiver chain. Combining this RF-SIC board with a custom-designed ring monopole antenna makes it possible to achieve >70dB of isolation at the RF front end across the entire 2-3GHz band. This high isolation between the nearby transmitter and receiver ensures wideband STAR operation. This paper describes the design approach and the associated fabrication challenges of the RF-SIC board.

Global manufacturing of integrated circuits provides cost-effective access to high-end fabrication facilities. Offshoring intellectual property (IP) to untrusted foundries, however, makes fab-less design houses vulnerable to several issues, such as reverse engineering, overbuilding, counterfeiting, IP piracy, and insertion of malicious circuits. Several hardware security methodologies and techniques have been proposed in the past few decades to thwart hardware attacks and reduce hardware vulnerabilities.Split-Fabric, a novel wafer-scale hardware security methodology that utilizes the silicon interconnect fabric (Si-IF) technology is proposed in this paper. Split-Fabric is a secure, scalable, low-overhead, and heterogeneous hardware security methodology that supports a fully-untrusted threat model. Two benchmark circuits, a nine-stage ring-oscillator and an 8x8 SRAM array, are designed and fabricated in part using TSMC 65 nm and in part using GF 45 nm to evaluate the performance overhead of Split-Fabric at different levels of obfuscation. According to simulation results, Split-Fabric exhibits orders of magnitude lower obfuscation overhead as compared to the split manufacturing approach.

Remote non-contact monitoring of human vital signs has recently received lots of attention due to the advancement and availability of millimeter wave (mmWave) radars. These sensors are significantly reduced in size, but still face serious electromagnetic (EM) propagation loss and signal obstructions resulting in lower signal-to-noise ratios (SNR). As mmWave received signals also have higher sensitivity to body motions, these effects typically degrade the accuracy of heart rate (HR) detection. To overcome this challenge, MIMO configuration can be used to improve the SNR level by taking advantage of its channel diversity. We use here a Frequency Modulated Continuous Wave (FMCW) radar from Texas Instruments (TI) at 77 GHz to collect data from 192 channels. Additionally, vital sign information is extracted using Arctangent Demodulation (AD) and Maximal Ratio Combining (MRC) combined with an adapted-wavelet Continuous Wavelet Transform (CWT) are utilized to demonstrate improvement of HR estimation accuracy.