Because of the tough competition inthe telecom business there is aconstant push for higher capacity anddata rates and the companies producingthe telecommunications equipment needmore cost effective products to stayahead of competitors. It is thereforeinteresting to evaluate thepossibilities to use unlicensedfrequency bands at higher frequenciesas a complement to the traditionallower frequency bands. This study isfocusing on the 5.8 GHz band, which ismainly used for WLAN applications. Akey component in most transmitter (TX)designs is is the quadraturemodulator, which upconverts theinformation signal to desired carrierfrequency. In this study an attempt toevaluate the commercially availablequadrature modulator ADL5375 at 5.8GHz. An AWR Visual System Simulator(VSS) model based on measurements ofkey parameters of ADL5375 isconstructed. An attempt is made to seewhether a TX design can pass thespecifications set by 3rd GenerationPartnership Project (3GPP) for theLong Term Evolution (LTE) standard. Totest this an LTE signal source wasalso constructed. No certainconclusions can be drawn withoutputting the modulator in a complete(TX) design but the results indicatethat it might be possible to use it ina (TX) design for the 5.8 GHz band.

This master thesis presents the design and implementation of a super heterodyne 5.8 GHz receiver system for wireless transmission of phase alternating line (PAL) composite video signals. The system is implemented using surface and hole mounted devices on four separate printed circuit board (PCB) stages. These stages include a 5.8 GHz radio front-end, a 480 MHz intermediate frequency (IF) stage, a local oscillator (LO) block and frequency demodulation circuit for frequency modulation (FM) signals. Each receiver stage is interconnected using sub-miniature version A (SMA) connectors. The radio front-end PCB consists of a low-noise amplifier (LNA), a 5.8 GHz distributed element pre-select filter and a passive double-balanced mixer. This mixer uses seven discrete injection frequencies at 5260-5380 MHz that are provided by the LO block using a programmable phase-locked loop (PLL) frequency synthesizer device. The IF stage uses an automatic gain control (AGC) feedback loop with a dynamic range of 60 dB. This AGC loop is implemented using a directional coupler, a detector device, a tuning circuit and a variable gain amplifier/attenuator (VGA). The IF at 480 MHz is selected with a 25 MHz surface acoustic wave (SAW) filter. The IF is demodulated to a PAL composite video format using a PLL FM discriminator device intended for direct-broadcast satellite (DBS) signals. This device is fitted to a separate demodulation stage in conjunction with a picture adjustment circuit and a FM de-emphasis network. The output of the demodulator stage is a 75 Ω PAL composite video signal.

With higher frequencies now being used in RFID systems, antennas are becoming much smaller resulting in more space on tags that can be used for innovative array designs to harvest more wireless energy. This master's thesis outlines and details a new methodology for designing and simulating the staggered pattern charge collector, a technique to improve harvesting wireless energy. Staggered pattern charge collectors enable RFID tag's to produce a higher DC voltage from a charge pump circuit by creatively using multiple arrays to increase the antenna power conversion gain without limiting the half power beamwidth. This thesis discusses the basics of patch antennas and charge pumps as well as an optimization technique for the staggered pattern array by maximizing integrated power conversion gain (IPCG). An example of a staggered pattern charge collector is fully specified from design through simulation, in preparation for fabrication. This methodology allows for the staggered pattern charge collectors to be designed, simulated, and fabricated quickly and effectively.

The thesis is aimed to design textile antennas that can operate in the ISM band 5.8 GHz. Attention is turned to practical exploitation of these antennas under regular conditions. Variations of the bandwidth of the antenna due to washing and waterproofing will be observed. Finally, the impact of the proximity of living tissue on the parameters of antennas will be studied.