No / This paper presented a planar printed multiple-input-multiple-output (MIMO) antenna with a dimension of 100 x 45 mm 2 . It composed of two crescent shaped radiators placed symmetrically with respect to the ground plane. Neutralization line applied to suppress mutual coupling. The proposed antenna examined both theoretically and experimentally, which achieves an impedance bandwidth of 18.67% (over 2.04-2.46 GHz) with a reflection coefficient < -10 dB and mutual coupling minimization of < -20 dB. An evaluation of MIMO antennas is presented, with analysis of correlation coefficient, total active reflection coefficient (TARC) and capacity loss. These characteristics indicate that the proposed antenna suitable for some wireless applications. Mutual Coupling Reduction of Two Elements Antenna for Wireless Applications. Available from: https://www.researchgate.net/publication/261064207_Mutual_Coupling_Reduction_of_Two_Elements_Antenna_for_Wireless_Applications [accessed Aug 1, 2017].

This thesis focuses on the design and implementation of low power Σ∆ ADCs in 130 nanometer CMOS technology. The design issues in the implementation of a third order ADC with a multi-bit and single bit quantizer are discussed. The advancement in CMOS technology has led to designing as much of electronics systems as possible with the digital circuits and digital signal processing replacing analog processing in most cases. Hence there is a need for digitizing analog signals with analog to digital converter (ADC). In communication systems this needs to be done immediately after the antenna in a receiver system. As this is difficult to implement due to high speed and high power consumption, RF signal is converted to a lower intermediate frequency (IF) and digitized. This work stresses low power implementation of high bandwidth Σ∆ ADCs for digitizing the IF. Design techniques involved in the implementation of a third order continuous time Σ∆ ADC with a 4 bit quantizer as well as a single bit quantizer for wide bandwidth are discussed. Moreover, a third order continuous time audio ADC implementation was also done. The behavioural modelling of the Σ∆ ADC along with clock jitter non-linearity model was developed and the issues in circuit design techniques are addressed. The continuous time ADCs’ major problem, namely, excess loop delay is discussed in detail and an efficient compensation technique for the same is implemented which allows a large reduction of power consumed by the ADC. Choice of loop filter architecture, quantizer and transistor level implementation are given that result in better immunity to offsets and process variations. Both the ADCs have been implemented using UMC 130 nm Mixed-mode RF-CMOS process and the simulation results for the multi-bit ADC gives a peak SNR of 56dB with a dynamic range of 65dB with power consumption of 2mW. The audio ADC achieves a peak SNR of 94.2dB with a dynamic range of 91dB.

The main goals of this thesis are to design and examine heterogeneous antennas for different wireless applications of a wide variety of EM spectrum requirements: which includes WLAN 5.0 GHz, WLAN (2.45 GHz), UMTS (1.92-2.17 GHz), 2G, UMTS, LTE, ultra-wideband (UWB) applications, and MBAN applications (2.4 GHz). Various techniques for expanding bandwidth, enhancing performance, and balancing the operation have been examined through comprehensive simulated and physically fabricated models. Thereafter, a compact DRA, for UWB applications is examined. The combined resultant effects of asymmetric positioning of DRs (2, 3 and 4 Cylindrical elements), defected ground technique, dimensions, and profile of the aperture give RF designers detailed scope of the optimization process. More resonances are achieved, and the bandwidth is improved. The obtained results show that, an impedance bandwidth of 133.0%, which covers the Ultra­ Wideband band (3.6GHz - 18.0GHz), with a maximum power gain of 9dBi attained. In addition, a compact conformal wearable CPW antenna using EBG-FSS for MBAN applications at 2.4GHz is proposed. They are designed using fabric materials suitable for daily clothing. The performance of the antenna is investigated in free space, on a layered biological tissue model, and on a real human body to evaluate SAR. When the antenna is combined with an EBG-FSS structure, isolation between the antenna and the human body is introduced. The results show that the FBR is enhanced by 13 dB, the gain by 6.55dBi, and the SAR is lowered by more than 94%. The CPW antenna demonstrated here is appropriate for future MBAN wearable systems. The design, investigation, and application of water level monitoring utilizing subsurface wireless sensor are covered in this thesis. A wideband double inverted-F antenna is designed and examined to overcome signal attenuation issues. The obtained result is feasible, which has an operating bandwidth of 0.8 to 2.17GHz, with a reflection coefficient better than 10 dB. Moreover, a field trial is conducted to evaluate the robustness of the antenna under extreme conditions. A very good efficiency was also demonstrated, with losses of under 20%. Further, the results from the field experiment established that the antenna is a reliable contender for wireless communication in such challenging environments. / Libyan Ministry of Higher Education / The full text will be available at the end of the embargo: 25th May 2025

Significant challenges to patient monitoring systems in a hospital environment include the reliable and energy-efficient transmission of data and their real-time display. This thesis proposes innovative and novel mechanisms for the reliable transmission of patient data in Body Area Network (BAN) communication, which simultaneously ensure high throughput, low data latency, and low energy consumption by implementing energy and QoS aware routing protocols. Five main contributions are made in this regard. Firstly, a novel patient monitoring system (ZK-BAN peering framework) is proposed for real-time hospital BAN communication that displays patient data on the display units by considering data privacy, low energy consumption, better control on the devices, and patient mobility. Secondly, a novel energy-aware peering routing protocol (EPR) is introduced in which the choice of next hop is based on the residual energy and geographic information of the neighbor nodes. EPR contains three main components: a Hello protocol, a neighbor table constructor algorithm, and a routing table constructor algorithm. Thirdly, a new modular QoS-aware routing protocol (QPRD) is designed to handle the ordinary and delay-sensitive data for BAN communication in hospitals. QPRD provides an end-to-end path delay mechanism to calculate the path delays of all possible paths from a source to destination and then chooses the best path with the lowest path delay for delay-sensitive packets. Fourthly, a novel modular QoS-aware routing protocol (QPRR) is developed to handle ordinary and reliability-sensitive data for BAN communication in hospitals. The modular architecture of QPRR includes five modules: a reliability module, a packet classifier, a Hello protocol module, a routing services module, and a QoS-aware queuing module. The proposed mechanisms for end-to-end path reliability calculation and data transmission using redundant paths ensure more reliable BAN communication. Finally, a new integrated energy and QoS aware routing protocol (ZEQoS) is designed to deal with ordinary, delay-sensitive, and reliability-sensitive data packets. Extensive simulations in the OMNeT++ based Castalia 3.2 simulator show that EPR, QPRD, QPRR, and ZEQoS perform better than other similar energy and QoS aware routing protocols.