Abstract—We describe a distributed position-based network protocol optimized for minimum energy consumption in mobile wireless networks that support peer-to-peer communications. Given any number of randomly deployed nodes over an area, we illustrate that a simple local optimization scheme executed at each node guarantees strong connectivity of the entire network and attains the global minimum energy solution for stationary networks. Due to its localized nature, this protocol proves to be self-reconfiguring and stays close to the minimum energy solution when applied to mobile networks. Simulation results are used to verify the performance of the protocol. Index Terms — Distributed algorithms, energy management, graph theory, mobile communication, network fault tolerance, networks, packet radio, portable radio communication, power measurement, protocols, radio repeaters. I.

Wireless communication has led to an explosive growth of emerging consumer and military applications of radio frequency (RF), microwave and millimeter wave circuits and systems. Future personal (hand-held) and ground communications systems as well as communications satellites necessitate the use of highly integrated RF front-ends, featuring small size, low weight, high performance and low cost. Continuing chip scaling has contributed to the extent that off-chip, bulky passive RF components, such as high-Q inductors, ceramic and SAW filters, varactor diodes and discrete PIN diode switches, have become limiting. Micro-machining or MEMS technology is now rapidly emerging as an enabling technology to yield a new generation of high-performance RF-MEMS passives to replace these off-chip passives in wireless communication (sub)systems. This paper reviews the progress in RF-MEMS from a device and integration perspective. The worldwide state-of-the-art of RF-MEMS devices including switches, variable capacitors, resonators and filters are described. Next, it is stipulated how integration of RF-MEMS passives with other passives (as inductors, LC filters, SAW devices, couplers and power dividers) and, active circuitry (ASICs, RFICs) can lead to the so-called RF-MEMS system-in-a-package (RF-MEMS-SiP) modules. The evolution of the RF-MEMS-SiP technology is illustrated using IMEC’s microwave multi-layer thin-film MCM-D technology which today already serves as a technology platform for RF-SiP. (Some figures in this article are in colour only in the electronic version) 1.

ABSTRACT: An RF low phase noise voltage-controlled oscillator is implemented with micromachined IC-compatible variable capacitors and three-dimensional coil inductor. Unlike conventional on-chip passive devices, the micromachined variable capacitors achieve a high-Q value above 60 at 1 GHz with a 15 % tuning range for a nominal 2 pF capacitance with 3 V tuning voltage. Three-dimensional inductors minimize the substrate loss and achieve a Q of 30 at 1 GHz with a 4.8 nH inductance. Both passive components are fabricated on silicon substrates and thus amenable to monolithic integration with standard IC process. The prototype VCO exhibits −136 dBc/Hz phase noise at 3 MHz offset frequency from the carrier, suitable for most wireless communication applications, in particular GSM. The VCO