Performance study of automatic transmit power control (ATPC) in point to point microwave link for rain attenuation problem in Malaysia

Point-to-point microwave system is the backbone link for mobile communication industry as well as for other applications. In tropical region particularly in Malaysia, rain attenuation is the major constraint for implementing microwave system above 10GHz. The extreme of propagation channel environment due to rain has brought to the research and development of an automatic transmit power control (ATPC) in microwave transceiver. ATPC varies the transmit power level in order to maintain the receive signal level (RSL) above the threshold for biterror- rate (BER) desired. This research project will cover three main scope of study. First estimated calculation of rain attenuation on terrestrial point-to-point microwave link based on rain data captured. This will involve the understanding and computational of rain attenuation modeling equation by ITU-R recommendation using the Matlab software. Second is the basic concept and operational of ATPC applied in transceiver module of microwave link. Finally the experimental performance analysis of ATPC on actual microwave link install in Celcom microwave network. The performance will be measured on receive signal level on the actual system with ATPC option enable and disable for a certain period of time with realtime rain faded signa

Technology Assessment and Experimentation Plan

An assessment is given of the critical and enhancing technologies necessary to build the basic personal terminal (BPT), the supplier, and the Network Management Center (NMC). The experimentation plan for testing the Personal Access Satellite System (PASS) utilizing ACTS is detailed. The experiment plan gives a list of candidate experiments and describes the proposed experimental set-up. ACTS will be used in the Microwave Switch Matrix (MSM) mode. The Microwave Switch Matrix - Link Evaluation Terminal (MSM-LET) at the NASA Lewis Research Center will serve as the microwave front-end for the PASS supplier and the NMC. Link budgets are given for both the forward and return links between the supplier and the basic personal terminal. The equipment required for the experiments is identified

High-gain self-steering microwave repeater, volume 1 Final engineering report, Jan. 1966 - Apr. 1969

Engineering model of high gain self steering microwave transponder and application to satellite communication link

The Experimental UWB Link

The experimental results from simple ultra wideband link are presented. The UWB link consisting of typical broadband microwave circuits built of commercially available components is able to send and detect unmodulated broadband electrical pulses with 20 MHz pulse repetition frequency. The system operates with approximately 60% of fractional bandwidth in 4GHz band with spectral density of -140dBW/Hz

Recent developments in the characterization of superconducting films by microwaves

We describe and analyze selected surface impedance data recently obtained by different groups on cuprate, ruthenate and diboride superconducting films on metallic and dielectric substrates for fundamental studies and microwave applications. The discussion includes a first review of microwave data on MgB2, the weak-link behaviour of RABiTS-type YBa2Cu3O7-d tapes, and the observation of a strong anomalous power-dependence of the microwave losses in MgO at low temperatures. We demonstrate how microwave measurements can be used to investigate electronic, magnetic, and dielectric dissipation and relaxation in the films and substrates. The impact of such studies reaches from the extraction of microscopic information to the engineering of materials and further on to applications in power systems and communication technology.Comment: Invited contribution to EUCAS2001, accepted for publication in Physica C in its present for

Superconducting Circuits for Quantum Simulation of Dynamical Gauge Fields

We describe a superconducting-circuit lattice design for the implementation and simulation of dynamical lattice gauge theories. We illustrate our proposal by analyzing a one-dimensional U(1) quantum-link model, where superconducting qubits play the role of matter fields on the lattice sites and the gauge fields are represented by two coupled microwave resonators on each link between neighboring sites. A detailed analysis of a minimal experimental protocol for probing the physics related to string breaking effects shows that despite the presence of decoherence in these systems, distinctive phenomena from condensed-matter and high-energy physics can be visualized with state-of-the-art technology in small superconducting-circuit arrays

Received optical power calculations for optical communications link performance analysis

The factors affecting optical communication link performance differ substantially from those at microwave frequencies, due to the drastically differing technologies, modulation formats, and effects of quantum noise in optical communications. In addition detailed design control table calculations for optical systems are less well developed than corresponding microwave system techniques, reflecting the relatively less mature state of development of optical communications. Described below are detailed calculations of received optical signal and background power in optical communication systems, with emphasis on analytic models for accurately predicting transmitter and receiver system losses