This letter presents a low‐noise amplifier with a 3 dB‐bandwidth, from 55 to 74 GHz, excellent noise performance and low power consumption based on a three‐stage common‐source topology. For the first time to the authors' best knowledge, an analytical equation that also considers the gate–drain capacitance is derived for the employed shunt–series transformer feedback input matching network. To enable shunt–series transformer feedback matching without significant gain reduction a highly asymmetric transformer is designed. Furthermore, a compact transformer‐implemented T‐shaped output matching network is investigated to minimize the required area. To prove these concepts, the circuit has been fabricated in a 22 nm fully depleted silicon‐on‐insulator technology. Thanks to the transformer‐based matching, an ultra‐compact active footprint of 0.039 mm ² is achieved. At a power consumption of 8.4 mW from a 0.41 V supply an average noise figure of 4.8 dB and a peak gain of 14.2 dB has been measured. In‐ and output matching better than −10 dB over the 19 GHz wide 3 dB‐bandwidth are demonstrated.

Several wireless communication technologies, including Wireless Sensor Networks (WSNs), are essential for Internet of Things (IoT) applications. WSNs employ a layered framework to govern data exchanges between sender and recipient, which facilitates the establishment of rules and standards. However, in this conventional framework, network data sharing is limited to directly stacked layers, allowing manufacturers to develop proprietary protocols while impeding WSN optimization, such as energy consumption minimization, due to non-directly stacked layer effects on network performance. A Cross-Layer (CL) framework addresses implementation, modeling, and design challenges in IoT systems by allowing unrestricted data and parameter sharing between non-stacked layers. This holistic approach captures system dynamics, enabling network design optimization to address IoT network challenges. This paper introduces a novel CL modeling methodology for wireless communication systems, which is applied in two case studies to develop models for estimating energy consumption metrics, including node and network lifetime. Each case study validates the resulting model through experimental tests, demonstrating high accuracy with less than 3% error.

In addition to implementing the core functionality, a design goal for modern circuits is reduced energy consumption. When options for improving active state efficiency are eventually exhausted, the next step is to aggressively minimize the duration a circuit is active to reduce overall energy consumption. Consequently, this article presents a top-down study on efficient duty-cycling of power amplifiers (PAs), spanning system-level considerations down to experimental measurements of a proposed V-band PA. A thorough analysis of the duty-cycling characteristics in a wireless transmitter reveals the significance of fast and efficient switching, particularly if minimal latency is desired and if energy consumption should scale linearly with required data rate. To be able to assess PAs in that regard, the related key characteristics as well as transient RF power measurements are discussed. To enable aggressive duty-cycling at circuit level, the switching process is studied for integrated millimeter-wave (mmWave) class-E PAs. Despite intrinsic switched mode operation at RF, transitions from sleep to active state are not instantaneous, but two phases are revealed: operating point switching (OPS) and large-signal rise in the load network. A kick-starter circuit for speeding up this transition is investigated. To prove these concepts, a two-stage 51 GHz 14 dBm SiGe PA capable of fast and efficient operational state switching is designed and fabricated. Its duty-cycling performance is measured in detail for both single-tone and modulated signals showing turn-on times in the nanosecond range. The results demonstrate highly efficient duty-cycling of data transmission at a cycle duration of just 1 μs for minimum latency. This article aims to allow system and circuit designers to better evaluate requirements for and performance of switchable mmWave PAs in context of duty-cycled communications.

Accurate current-consumption estimation in IEEE 802.15.4 Wireless Sensor Networks requires linking network operation to the hardware states that determine node energy use. This paper proposes a cross-layer energy-modeling methodology that combines experimentally characterized Current Consumption Profiles (CCPs), protocol-derived state-duration models, topology-dependent workload, and a two-stage probabilistic model for retransmissions. The methodology distinguishes structurally constrained states, empirically modeled state durations, and discrete stochastic communication events. In the evaluated CC2538–ContikiMAC implementation, transmission duration is modeled from payload size, ContikiMAC strobe activity, and Clear Channel Assessment (CCA) timing, while sleep duration is obtained from the residual communication-cycle constraint. Retransmission occurrence is represented by a Ridge-regularized logistic model using measured CCA duration, whereas the positive retry count is represented by its calibrated conditional mean. The resulting probabilistic component is integrated with the deterministic CCP formulation to estimate the additional charge associated with retry-enabled communication events. Full-network verification across 30 node–condition observations yielded an overall MAPE of 10.81%, WMAPE of 10.51%, and condition-specific MAPEs ranging from 4.60% to 15.78%.