Miniaturized Planar Crossover Using Microstrip Stub Loaded Coupled Lines

Abstract

A novel symmetrical planar crossover is presented in this paper. The proposed resonator consists of coupled lines loaded by U-shape stubs, which two similar of them are integrated to create two passband paths at 2.09 GHz for wireless communication systems. To analyze the proposed structure a LC equivalent circuit is proposed for the coupled lines then the resonance condition is obtained. The isolation between two channels is well improved so that S₂₁, S₄₁ and S₃₂ are −29.9, −26.59 and −26.4 dB at 2.09 GHz. Meanwhile, 0.57 dB insertion loss and a compact size of 0.202λ_g×0.208λ_g (21.6×22.2 mm²) are obtained where λ_g is the guided wavelength calculated at the resonance frequency. Also, a phase analysis is done that shows exactly 0˚ phase shift between two paths (S₃₁ and S₄₂) at the resonance frequency. To verify the introduced methodology, the designed crossover is fabricated and measured. There is a good agreement between the simulated and measured results.

KEYWORDS:

• Compact size
• Coupled lines
• Crossover
• Isolation
• Microstrip
• Phase analysis

Additional information

Notes on contributors

Abbas Rezaei

Abbas Rezaei is assistant professor of electrical engineering in Kermanshah University of Technology. His current research interests include computational intelligence, RF and microwave, and nanotechnology. Email: [email protected], [email protected]

Leila Noori

Leila Noori received her BEng and MS in electronics engineering from Razi University, Kermanshah Iran in 2007 and 2011, respectively. She received her PhD in electronics engineering from the Shiraz University of Technology, Shiraz, Iran in 2015. Her main research interests are designing of RF and microwave circuits. Corresponding author. Email: [email protected]