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Sub-terahertz (THz) wireless communication links require low-SWaP (size, weight, and power) software defined radio (SDR) modems to achieve efficient and reliable data transmission. This research presents the design, development, and experimentation of an SDR system operating in the 135-150 GHz frequency range, utilizing simple I/Q modulation techniques such as differential binary phase shift keying (DBPSK). The system integrates advanced components, including Virginia Diodes (VDI) 110-170 GHz compact upconverter (CCU) and compact downconverter (CCD), high-gain lens horn antennas from Anteral (40 dBi), and the Xilinx RF-SoC ZCU-111 for real time DSP. A 500 MHz IF is implemented on RF-SoC with baseband bandwidth 64 MHz and data rate 64 Mbps via DBPSK modulation. For 20 dBm transmit power at 147 GHz, the nearfield SNR was measured to be 55 dB at 1m lens-to-lens separation for a baseband of 64 MHz. Simulation models of propagation predict 64 Mbps is possibly viable at up to 2 km in a point-to-point connection for a BER of < 10−3. The SDR was realized on the Xilinx PYNQ platform, offering a user-friendly interface while being adaptable to high data rate applications. This digital design is particularly suited for deployment in scenarios such as vehicle-to-vehicle communication, backhaul networks, and data center level interconnects. The research explored challenges related to synchronization, signal integrity, and environmental sensitivity, which are critical for maintaining reliable communication in a 147 GHz channel. A real-time text messaging application demonstrated correct operation of the PYNQ modem. 

Wireless links at sub-THz bands require low-SWaP SDR modems. We report early design experimentation of an SDR operating in the 130–150 GHz band, with ASK/BPSK/QPSK modulation on I/Q channels, at a maximum data rate of 128 Mbps. The design utilizes 110–170 GHz front-ends from Virginia Diodes, and Xilinx RF-SoC ZCU-111 for DSP operations. A 1 GHz baseband example at 145.5 GHz is provided. The experiment uses horn antennas with 21 dB gain. The SNR is about 40 dB without cross correlation gain in the detector which provides an additional 15 dB in link margin. Real-time bit rate of 128 Mbps is achieved. Example applications include vehicle-to-vehicle, vehicle-to-infrastructure, backhaul, device-to-aerostat. This paper provides a platform from which further design work will lead to increased data rate and/or range, and enhance security through encryption. Future designs will facilitate digital interfaces, such as, ethernet, AXI, PCIe and USB-C. 

UAVs have been studied and manufactured to help create wireless communications networks that are more flexible and cost-effective than a typical wireless network. These UAV networks could help bridge the digital divide in rural America by providing wireless communications service to areas where cell companies find it too expensive to build conventional cell towers. To test different aspects of a UAV-based millimeter-wave frequency network, we created a MATLAB simulation. The simulation visualizes a digital twin of a farm in eastern Nebraska where UAVs are tested. The simulation allows for link budgeting and interference management calculations by accommodating changes in transmitter and receiver location, frequency of the network, power of the transmitted signal, weather conditions, and antenna specifications. The simulation is able to calculate critical network values such as signal-to-interference-plus noise ratio (SINR), path loss, atmospheric loss, and antenna gains under dynamically changing conditions.