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The authors propose the design of a compact mechanically frequency and pattern reconfigurable patch antenna. The frequency tuning is achieved by changing the positions of two adjustable shorting screws which are used to modify the length of the antenna radiating patch. Simulated and measured results are carried out to validate the proposed approach. When the screws are symmetrically positioned, the measured operating frequency can be tuned from 2.95 to 5.16 GHz without degrading the radiation characteristics over the entire comparatively wide measured tuning range of 54.5%. The antenna main radiating beam can be tilted from θ = 0° to θ = 30° when the screws are asymmetrically positioned. The measured gains and efficiencies range from 3.01 to 5.53 dBi and 68 to 74%, respectively. The overall antenna size is only 0.39λ0 x 0.39λ0 x 0.02λ0. [ABSTRACT FROM AUTHOR]

A novel composite phase-shifting transmission line (TL) with designable characteristics is presented, which can be used to achieve arbitrary phase of the transmission coefficient at any required frequency with a certain length of the TL. An empirical formula is given of the relationship between the phase and physical length of the composite TL at a required frequency. A sample of 0 phase-shifting TL is designed in details, and is verified by the full-wave simulation. At the required frequency of 5 GHz, the amplitude of S21 is equal to -0.23 dB with a phase of -0.467°. The electric length is only 0.21λ0, which has been decreased by 68.5% compared to the conventional microstrip line. Using the proposed composite TL, an antenna array is designed with two radiation patches excited by the novel series feed-line. The detailed procedure of such design is presented. The lowest reflection coefficient is exactly achieved at the required frequency of 5 GHz. The maximum radiation is obtained at θ0 = O°, which indicates that the 0 phase-shifting TL works very well. The sample is also fabricated and good agreements between simulation and measurement results are obtained. [ABSTRACT FROM AUTHOR]