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A lightweight planar antenna element with optimized feed for use onboard spacecraft

100%

Wincza K. , Kabacik P.

tom nr 2

53-56

This paper is a report on low gain antennas (LGAs) manufactured with bonded lightweight materials. These antennas can sustain large temperature variations and are capable of functioning in modern miniature spacecraft, mainly in the telemetry, command and ranging (TC&R) links. When made of cheaper materials, the proposed circularly polarized antenna can be widely used in the base stations of short-range wireless systems. The recommended operating frequencies are between 1 and 8 GHz. One major technical consideration is obtaining the required high quality of circular polarization with as low space demands as possible. A lightweight 90? polarizer, printed on a dielectric membrane and operating over a broad bandwidth, is proposed for the antenna feed. Owing to the bandwidth advantage of the polarizer and the use of carefully designed aperture coupled feed, the electrical characteristics maintain good properties over a wide frequency range (15%).

Wideband Nine-Port Reflectometer

80%

Odrobina S. , Staszek K. , Wincza K. , Gruszczynski S.

tom Vol. 64, No. 1

19--25

The paper presents a wideband nine-port reflectometer realized as a cascade connection of six- and five-port reflectometers. It is shown that such a solution allows for a convenient adjustment of circuits’ parameters in order to provide significantly reduced measurement uncertainty with respect to other reported reflectometers. Simultaneously, the proposed network features a simple and flexible design. For the experimental verification, the proposed nine-port reflectometer has been manufactured and incorporated into the system intended for reflection coefficient measurements within the frequency range 2.5 - 3.5 GHz. The obtained results are in an excellent agreement with the values measured using a commercial VNA.