Konstantinos Voudouris

Development of a 60 GHz Substrate Integrated Waveguide planar diplexer

A 60 GHz frequency band planar diplexer based on Substrate Integrated Waveguide (SIW) technology is presented in this research. The 5th order millimeter wave SIW filter is investigated first, and then the 60 GHz SIW diplexer is designed and been simulated. SIW-microstrip transitions are also included in the final design. The relative bandwidths of up and down channels are 1.67% and 1.6% at 59.8 GHz and 62.2 GHz respectively. Simulation shows good channel isolation, small return losses and moderate insertion losses in pass bands. The diplexer can be easily integrated in millimeter wave integrated circuits.

Millimeter-wave passive front-end based on Substrate Integrated Waveguide technology

An integrated millimeter-wave passive front-end based on Substrate Integrated Waveguide (SIW) technology is presented in this research. It consists of a diplexer which acts as channel separator between transmit and receive chains and a common 8×8 SIW slot antenna array for both transmission and reception. Simulation results show very good performance in terms of channel bandwidth, insertion loss, out-of band rejection and channel-to-channel isolation as well as good performance in terms of radiation characteristics at 60 GHz band. The proposed passive front-end can be easily integrated with active components and provide a fully-integrated transceiver front-end adopting the System-on-Substrate concept for millimeter-wave wireless applications.

A 60 GHz Planar Diplexer Based on Substrate Integrated Waveguide Technology

This paper presents a millimeter-wave, 60 GHz frequency band planar diplexer based on substrate integrated waveguide (SIW) technology. Diplexer consists of a pair of 5th-order SIW bandpass channel filters with center frequencies at 59.8 GHz and 62.2 GHz providing 1.67% and 1.6% relative bandwidths, respectively. SIW-to-microstrip transitions at diplexer ports enable integration in a millimeter-wave transceiver front end. Measurements are in good agreement with electromagnetic simulation, reporting very good channel isolation, small return losses, and moderate insertion losses in the passbands. The proposed SIW planar diplexer is integrated into a millimeter-wave transceiver front end for 60 GHz point-to-point multigigabit wireless backhaul applications, providing high isolation between transmit and receive channels.

Next generation millimeter wave backhaul radio: Overall system design for GbE 60GHz PtP wireless radio of high CMOS integration

In this paper we present the implementation of an experimental FDD, QPSK, millimeter-wave radio modem (57–64 GHz) for Point to Point (PtP) wireless backhaul applications. The transceiver supports GbE targeting a two-chip solution plus the antenna subsystem, aiming at highly integrated functions in 90nm CMOS technology, for a range of more than 1km. Achieving these levels of overall integration and silicon implementation requires many technological challenges and innovative design approaches. Furthermore, it allows for drastic changes of relevant cost factors enabling the wireless backhaul deployment for broadband services. The present paper is an outcome of the NexGenMiliwave project aiming to prove that it is possible to provide integrated solutions in silicon, based on demanding high frequency PtP requirements and significantly reduce the cost of the relevant backhaul network deployment.

A Multi-Hop Relay Station Software Architecture Design, on the Basis of the WiMAX IEEE 802.16j Standard

In order to enable rapid and cost-effective deployment of WiMAX networks, relay technology which does not require backhaul line, can be considered as an essential feature for performing a successful business development. In the scope of a proposed Multi-Hop relay network architecture, (based on the recently developed IEEE 802.16j standard in order to enhance throughput, network coverage and capacity density), we provide an essential description of the Relay Station Software architecture design (PHY and MAC layers architecture), as it has been proposed by the REWIND European Research Program. The corresponding relay node is based on a highly integrated SoC device, which incorporates all baseband processing (PHY, MAC and CS), networking and control processors required for the relay station functionality. Thus, the Relay node software shall run all the PHY, MAC, scheduler and networking functionalities, required to operate a complete BS with relay functionality, and to integrate the node into the relay network.

2

A 2 × 2 Switch Matrix operating at the 3.3-3.8 GHz frequency band is presented. The design is based on PIN diode switch elements. The achieved isolation is below 80 dB, while the insertion loss is less than 2 dB for the full frequency band. The proposed 2 × 2 Switch Matrix is used as the antenna switching element in the RF Front-End of a WiMAX Relay Station, supporting both Time-domain Transmit and Receive and Simultaneous Transmit and Receive operation in Time Division Duplexing mode.

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Results from a practical study of a direct conversion receiver (DCR) and its subsections, namely, power splitter, branch coupler hybrid, coupled lines bandpass filter, lowpass filter, balanced mixer, and oscillator, are presented. The receiver is designed for the 2-GHz frequency band, with particular reference to personal communications terminals for the digital European cordless telecommunications (DECT) standard. The DCR overall performance, based on measured figures of individual subcircuits, is analyzed with the aid of the Eesof-Omnisys simulator. Typical value for the signal-to-noise ratio is 12 dBm for 10/sup -3/ bit-error rate. The receiver can tolerate amplitude and phase mismatches of 3% and 5 degrees , respectively, as well as 1.2-kHz local oscillator drift. The dynamic range is 80 dB. The performance of the DCR fits well with the DECT specification.<<ETX>>

2 Switch Matrix for WiMAX Relay Station Applications

This paper aims at describing the advantages of using relay and repeater elements in a wireless network and especially in a network based on WiMAX technology. Apart from a description of the relay and repeater entities, a comparison between them is presented based on computer simulations. All presented material is based on the findings and results of the FP7-REWIND project.

Effects of amplitude, phase, and frequency imperfections on the performance of a direct conversion receiver (DCR) for personal communication systems

5th order millimeter-wave bandpass filter design and modeling based on Substrate Integrated Waveguide (SIW) technology is presented in this research. Two 60 GHz bandpass filters are designed and been simulated providing 1.67% and 1.6% relative bandwidths at 59.8 GHz and 62.2 GHz respectively. SIW-microstrip transitions are included in the final designs. Simulation shows small return losses, high out-of-band rejections and moderate insertion losses in pass bands. The proposed SIW filters can be easily integrated in millimeter-wave integrated circuits.

Relay vs. Repeater Architectures in WiMAX

A relay station (RS) is a smart transceiver used under a 4G wireless network in order to extend network’s coverage and capacity. It uses an antenna system that includes an antenna for connecting the relay with the end users (access link) and the RS with the base station (backhaul link). In this paper, a 7.9dBi access and 11.4dBi backhaul antennas are presented for the frequency range of 3.3 to 3.8GHz. The antennas are simulated and fabricated, and relevant measured results in terms of return loss and radiation pattern are presented and analyzed. Considering that the planes of those two antennas are positioned in an angle ω (omega), two antenna configuration geometries are tested in terms of coupling. The experimental results of S21 for several values of the angle ω showthat the interaction between the radiating elements is dependent on their relative position. Simulated and experimental results are in good agreement, showing coupling typically less than −40dB. A comparison in terms of coupling between the proposed antennas and commercial ones proves that the suggested antennas provide 10dB lower coupling.