A New Equal Power Quadrature Branch Line Coupler for Dual-Band Applications

Abstract

Abstract-We present a new equal power quadrature branch line coupler (BLC) for dual-band applications in this paper. A new topology of the dual-band quarter wavelength transmission lines (TL) with the derivation of design equations is also introduced. The proposed BLC is designed using Advanced Design System (ADS) and fabricated on Rogers 5870 at 0.9 GHz and 2.4 GHz center frequencies. The design approach for the proposed dual-band BLC is endorsed by the simulated and measured results. A comparative analysis of this BLC with the previous BLCs is also carried out.

A Dual Band Branch Line Coupler With Wide Frequency Ratio

“…Finally, Z E and Z O are obtained as (17) and (18) at frequency f 1 and f 2 respectively, by putting the value of θ 1 and θ 2 from (15)- (16) into (11)- (12).…”

“…Multiband BLC is a key component to design a multiband system, needed for the migration and up gradation of the wireless communication industry. Many structures and methods adopted to design dual band BLC such as T shaped TL [11], [12], π shaped TL [13], center tapped stub [14], coupled line (CL) with short stub [15], parallel combination of CL and TL [16], port extension [17], [18], CLs [19]- [22], dual TL [23], folding of TL [24], and CL with TL [25]. The techniques for dual band BLC presented in [11]- [25] are applicable only when the frequency ratio (k) between two operating frequencies is ≤4.…”

A New Coupled-Line Based Dual-Band Branch-Line Coupler With Port-Extensions

“…Conventional single band BLCs are implemented using quarter wavelength long branches resulting in spurious responses only at the odd harmonics of the fundamental frequency [1]. In contrast, multi-band designs are implemented by adding additional stubs [4] and half-wavelength sections [5] to the conventional structure, modifying the coupled-lines structures [6] or some other unique BLC structures [7,8], by port-extension techniques [9][10][11], etc. Over the years, numerous works have been reported on different aspects of dual-band coupler performance, for example, bandwidth control [12] and enhancement [13], miniaturization [14], wider band-ratio support [15], arbitrary port impedance [11], and arbitrary power division [9-11, 16, 17].…”

Planar Dual-Band Branch-Line Coupler With Large Frequency Ratio

“…based electromagnetic bandgap (EBG) [16] or composite right/left-handed (CRLH) TL [17] have also been reported for designing the dual-band couplers. Further designs reported the parallel combination of coupled line and TL [18], port extension [19], coupled lines [20], [21], and so on. In [10], coupled line based quarter-wavelength opened/ shorted stub modification was made to the conventional branch-line coupler to realize dual/tri-band operations, where the achieved frequency ratio is small, while the circuit is complex and bulky.…”