An array of stagger‐tuned printed dipoles as a broadband frequency selective surface

Abstract

In addition, a connection metal line of 1 mm width was printed between the two side-feeds. This connection metal line mainly serves as a delay line in the proposed antenna to provide a 90°phase difference between the two side-feeds. This desired phase difference can be obtained by adjusting the distance (1.5 mm in this study) between the connection metal line and the ground conducting patch in the proposed design. Also notice that two small notches were cut near points A and B in the ground conducting patch to avoid the shortcircuiting of the two side-feeds to the ground.To excite the proposed antenna with right-hand CP operation for GPS operation, a 50 ⍀ microstrip feed line printed on the test circuit board is connected to the side-feed at point A. In this case, the side-feed at point A will have a 90°phase lead, as compared to the side-feed at point B. This condition can lead to successful excitation of two orthogonal resonant modes of equal amplitudes and 90°phase difference for right-hand CP operation. Also note that, if left-hand CP operation is desired for some other applications, the microstrip feed line can be connected to the side-feed at point B. In this case, the side-feed at point A will have a 90°phase lag, as compared to the side-feed at point B, thereby making possible the generation of a left-hand circularly polarized wave. EXPERIMENTAL RESULTS AND DISCUSSIONABSTRACT: In this paper, the frequency selective property of an array of rectangular dipole microstrip patches resonant at three different ABSTRACT: In this paper a birefringence interferometer is used for detecting both change in reflectivity and surface deformation caused by photothermal effect or thermal waves excited by anyother pump source. The instrument is very simple, with high immunity against noise and sensitivity.

Microwave Screen With Magnetically Controlled Attenuation

“…For example, pin diodes are proposed for the design of adaptive radar absorbers [1,2] and tunable frequency selected surfaces [3,4]. Other principles of the design of tunable microwave materials, such as ferroelectrics [5] and conducting polymers [6] controlled by electric field, or ferromagnetic materials controlled by magnetic field [7], are also considered for freespace applications.…”

Design of an Aperture Type Frequency Selective Surface with Sharp Roll -off

“…The patch type FSS shows band reject property and aperture type FSS shows band pass property. For this nature FSS is used in different devices like antenna radome, frequency subreflector system and many other military applications [2,3]. This type of single layer frequency filters suffers from very poor filtering due to bad roll off.…”