Weakly coupled directional coupler with simultaneous wide bandwidth and high directivity. Issue 5 (28th January 2019)

• Record Type: Journal Article
• Authors: Hammad Akhtar, M.; Ayaz Zakir, M.; Cheema, Hammad M.
• Is Part Of: Microwave and optical technology letters. Volume 61:Issue 5(2019:May)
• Page Start: 1259
• Page End: 1262
• Publication Date: 2019-01-28
• Subjects: coupled‐line coupler -- high directivity -- intrinsic impedance -- isolation enhancement -- weakly coupled; Microwaves -- Periodicals; Optics -- Periodicals; 621
• DOI: 10.1002/mop.31723
• Languages: English
• ISSNs: 0895-2477

Abstract

Abstract: Weakly coupled directional couplers are known to have poor directivities and narrow bandwidths. In order to improve both parameters simultaneously, this article demonstrates for the first time, that combination of shunt reactive loading and external impedance matching, results in high directivity, and wideband performance. The proposed directional coupler, fabricated on a Rogers 6035HTC substrate, demonstrates directivity greater than 20 dB over a fractional bandwidth of 35%, which is the highest reported for microstrip based design having weak coupling factor of 30 dB.