A novel balun being the structure of a Wilkinson power divider is suggested and fabricated. One of the power dividing paths in the suggested balun uses a conventional λ/4 transmission line for -90° phase shifting, and the other path uses a composite right/left-handed -λ/4 transmission line for +90° phase shifting with four series capacitors and three parallel inductors. In addition, the suggested balun uses two 50-Ω resistors and a conventional 50-Ω transmission line of λ/2 electrical length between the two output ports, achieving good isolation and reflection values of two balanced ports. The suggested balun is simulated by the advanced design system simulation program and fabricated on TLX-9 20-mil substrate. The fabricated balun has a very good values of S 11 = -27.46 dB, S 21 = -3.40 dB, and S 31 = -3.28 dB, a phase difference of -179.5°, a magnitude difference of 0.12 dB, and a delay difference of 0.1 ns, with S 22 = -36.28 dB, S 33 = -27.19 dB, and S 32 = -25.2 dB at 1 GHz, respectively.
Index Terms: Balun, CRLH, Wilkinson-type balunOpen Access J. lnf. Commun.
A low‐profile phased array antenna with a low sidelobe was designed and fabricated using a genetic algorithm (GA). The subarray distances were optimized by GA with chromosomes of 78 bits, a population of 100, a crossover probability of 0.9, and a mutation probability of 0.005. The array antenna has 24 subarrays in 14 rows, and is designed as a mobile terminal for Ku‐band satellite communication. The sidelobe level was suppressed by 6.5 dB after optimization, compared to the equal spacing between subarrays. The sidelobe level was verified from the far‐field pattern measurement by using the fabricated array antenna with optimized distance.
In this paper, the stair-planar phased array antenna with tracking beam is introduced and the beam pointing characteristics are theoretically analyzed from numerical simulation. The vehicular antenna was developed as engineering model to provide the satellite internet services in mobile environment. Especially, radiator subarrays of this antenna are arranged like stairs to design for low profile. This structure brings about the pointing error between the main and tracking beams due to the difference of each frequency. To solve this trouble, two treatments using RF cable length compensation and Znd level phase compensation are investigated. In addition, this analytic model of beam steering will help to design and evaluate the antenna beam pattern.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.