A method has been devised to experimentally characterize a packaged GaAs Schottky barrier diode by inserting it into a microstrip test mount. The nonlinear equivalent circuit parameters of the diode are determined by a small-signal test method. A large-signal measurement using the same test mount has also been configured to determine the power conversion efficiency from microwave to DC as well as determining the de-embedded network impedance of the diode. A nonlinear circuit simulation program using a multireflection algorithm is used to verify the experimental results for the 2.45-GHz diode. A Ka-band mixer diode is simulated for a 35-GHz rectenna. Based on the simulation results, a patch-type 35-GHz rectenna is designed and tested in a waveguide simulator. The efficiency is 29% with 120-mW input power. Because the diode could generate undesirable harmonic radiation, a frequency-selective surface is designed to reduce the second harmonic radiation for a 2.45-GHz rectenna. Theoretical results agree fairly well with experiments for all these studies. >

Theoretical and experimental investigation of a rectenna element for microwave power transmission

The concept of SPS-WPT envisions the generation of electric power by solar energy in space for use on earth. The system would consist of an orbiting platform to gather solar energy and convert it to electric and microwave power in space. A microwave transmission system would be employed to send the electric power to earth. A power-receiving antenna (rectenna), on the ground or offshore, would convert and collect the transmitted microwave energy in a form of electricity suitable for the common electric utility distribution infrastructure. Some environmental and health concerns are discussed.

Space solar-power stations, wireless power transmissions, and biological implications

Discusses the history of the concept of power generation on a satellite and its transmission to the surface of the Earth. The implications for human health are considered together with means for alleviating possible health risks.

Space solar-power station, wireless power transmission, and biological implications

The conceptual design of a ground-based microwave power transmission system is described. This system is intended to supply electrical power via an air link to a high-altitude (21 km) powered platform. The platform must be equipped with the required instrumentation (RECTENNA) to convert the RF energy to dc power.

Design study for a gound microwave power transmission system for use with a high-altitude powered platform

In 2002, a phased, multi-year approach to space solar power has been published. Following this plan, several activities have matured the concept and technology further in the following years. Despite substantial advances in key technologies, space solar power remains still at the weak intersections between the space sector and the energy sector. In the 10 years since the development of the European SPS Programme Plan, both, the space and the energy sectors have undergone substantial changes and many key enabling technologies for space solar power have advanced significantly. The present paper attempts to take account of these changes in view to assess how they influence the prospect for space solar power work for Europe.

Prospects for space solar power in europe

Measured characteristics of the spectrum of typical converters and the distribution of radiated Radio Frequency (RF) energy from the terminals (transmitting antenna and rectenna) of a beamed microwave power subsystem are presented for small transmitting and receiving S-band (2.45 GHz) subarrays. Noise and harmonic levels of tube and solid-state RF power amplifiers are shown. The RF patterns and envelope of a 64 element slotted waveguide antenna are given for the fundamental frequency and harmonics through the fifth. Reflected fundamental and harmonic patterns through the fourth for a 42 element rectenna subarray are presented for various dc load and illumination conditions. Bandwidth measurements for the waveguide antenna and rectenna are shown.

R. M. Dickinson

Papers

Beamed microwave power transmitting and receiving subsystems radiation characteristics