Modified design of Wilkinson power divider for harmonic suppression

Abstract

A modified design that can reject the nth harmonic output in the Wilkinson power divider is presented. After adding transmission lines between the resistor and each output port of the traditional design, a solution of the modified Wilkinson divider can be found. Experimental results show the third harmonic suppression to be 237.0 dB, while maintaining conventional performance at the fundamental frequency.Introduction: A Wilkinson power divider provides port matches and complete isolation at a frequency and its odd harmonics. It can also perform an insufficient division under port mismatches and incomplete isolation at its even harmonics [1]. Additional rejection filters become necessary in order to suppress its harmonics in the divider.In [2], a power divider with nth harmonic suppression was proposed by adding open stubs at the centre of quarter-wave transformers. However, its physical dimensions become larger owing to the added stubs and an inductor in parallel with a resistor should be added. Subsequently, design methods featuring an asymmetric spiral defected ground structure, an anti-coupled line, and a bandgap cell in transformer lines [3][4][5] are used to suppress the nth harmonics. The combination of bandgap elements and open stubs was found in [6]. However, there are disadvantages in their inherent structures according to the design frequency and the desired suppression terms.In this Letter, by adding stub segments between the resistor and the output ports and then modifying the traditional design parameters, a valid solution to reject the nth order component is found.

A Novel Harmonics-Suppression Coupled-Line Gysel Power Divider for Complex Terminated Impedances

“…To overcome this drawback, the Wilkinson PDs, couplers, and filters with harmonics suppression have been studied by utilizing equivalent pi-shaped, T-shaped, and pi-T hybrid-shaped open-stub transmission lines (Guan et al, 2012a), using two open stubs and an inductor (Yi & Kang, 2003) or adding a transmission line between the resistor and each output port (Kim et al, 2009). Other structures, including an asymmetric spiral defected ground structure (DGS; Woo & Lee, 2005), a microstrip electromagnetic band gap (EBG) cell (Lin et al, 2007), and stubs and an extended line , are also used in passive components for obtaining harmonics-suppression performances.…”

“…Other structures, including an asymmetric spiral defected ground structure (DGS; Woo & Lee, 2005), a microstrip electromagnetic band gap (EBG) cell (Lin et al, 2007), and stubs and an extended line , are also used in passive components for obtaining harmonics-suppression performances. Unfortunately, these technologies (Yi & Kang, 2003;Kim et al, 2009;Woo & Lee, 2005;Lin et al, 2007) need backside etching or additional lumped elements, and the corresponding circuits will have a large size. In addition, not all the technologies can have the analytical solutions, and the desired results are achieved mainly by computer optimization.…”

A Modified Microstrip Wilkinson Power Divider With High Order Harmonics Suppression

“…In recent years, some new WPD with multiband operating frequencies [5][6][7][8][9][10][11] or harmonic suppression [12][13][14][15][16][17][18] have been proposed. These structures are proposed to simplify the circuit structure and reduce the circuit area.…”

“…Spur-lines are used to achieve the stopband at the spurious frequency in [16]. In [17,18], the methods for one order harmonic suppression are presented. It is significant to proposed a method for the design of a WPD with high orders harmonics suppression, closed form solution, and fully matching at the input and output ports.…”

Improved dual-frequency Wilkinson power dividers with Defected Ground Structure

“…In recent years, there is a widespread demand in dual-band power dividers, which are used in multiband mobile phones [1,2,3,4,5]. Different schematics of dual-frequency Wilkinson power dividers have been discussed in [2,3,7] and [8].…”