A Novel Arbitrary Terminated Unequal Coupler With Bandwidth-Enhanced Positive and Negative Group Delay Characteristics

Wu³

et al. 2019

Circuit Theory & Apps

Self Cite

Summary A novel compact arbitrary terminated power divider with bandwidth‐enhanced negative group delay (NGD) characteristics is proposed. The NGD characteristics are controlled by characteristic impedances of transmission lines and the coupled line between two output ports. Flat and wide NGD bandwidth is produced by using the combination of a series resistor and short‐circuited coupled‐line section. The complete closed‐form equations are presented. For experimental demonstration, a prototype is designed and fabricated at f0 of 2.14 GHz. The measured results indicate that the proposed power divider is able to realize wide NGD bandwidth and good NGD flatness.

“…The Y ‐matrix of the proposed NGD power divider can be established as

Y = ([], \begin{array}{c} Y_{A} + Y_{C} & Y_{12} & Y_{13} \\ Y_{21} & Y_{A} + Y_{B} & Y_{23} \\ Y_{31} & Y_{32} & Y_{B} + Y_{C} \end{array}),

where

({, \begin{array}{l} Y_{A} = Y_{C} = - {jY}_{1} cot ((), θ) \\ Y_{B} = \frac{Y_{2} ((), Y_{in} cot ((), θ) - {jY}_{2} {cot}^{2} ((), θ) + {jY}_{2})}{2 Y_{2} cot ((), θ) + {jY}_{in}} \\ Y_{12} = Y_{21} = Y_{13} = Y_{31} = {jY}_{1} csc ((), θ) \\ Y_{23} = Y_{32} = \frac{Y_{2}^{2} {csc}^{2} ((), θ)}{Y_{in} - j 2 Y_{2} cot ((), θ)} \end{array}) .

…”

Section: Theory and Designmentioning

confidence: 99%

Compact arbitrary terminated power divider with bandwidth‐enhanced negative group delay characteristics

Wu³

et al. 2019

Circuit Theory & Apps

Self Cite

“…Moreover, the magnitude of transmission coefficient and group delay of the proposed NGD Gysel power divider at f 0 are, respectively, found as (11) and (12) assuming…”

Section: Design Theorymentioning

confidence: 99%

“…It can be found from (8), (9), and (11), the magnitude of transmission coefficient (i.e. IL) is only controlled by R. And (9) and (12) imply that R, k, Z c , Z 02 , and Z 03 have effects on GD. Figure 3 gives the effects of R on IL and τ × f 0 of the proposed NGD Gysel power divider with Z 02 � 100 Ω, Z 03 � 100 Ω, k � 0.17, and Z c � 550 Ω.…”

Section: Design Theorymentioning

confidence: 99%

“…e NGD power dividers [9][10][11][12] have larger NGD and IL bandwidths, but only one output port of the power divider has NGD characteristics and the IL is destructive (larger than 15 dB). Compared with [9][10][11][12][13], the proposed NGD Gysel power divider has a much lower IL. For the NGD power divider in [14], its isolation is poor (less than 16 dB), and it has a narrow IL bandwidth.…”

Section: Power Divider With Single-stage Rcscl Networkmentioning

confidence: 99%

“…NGD power dividers can be used to compensate the group delay through different transmission paths in the supply-modulated power amplifier. Recently, some NGD power dividers have been presented in [9][10][11][12]. However, only one output port of these power dividers has the NGD characteristics and suffers from very high insertion loss (IL), which is more than 15 dB.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Novel Gysel Power Dividers with Negative Group Delay Characteristics

Zhu

International Journal of Antennas and Propagation

Zhou

et al. 2019

A novel Gysel power divider with negative group delay (NGD), good matching, and low insertion loss is proposed. Resistors connected with short-circuited coupled lines (RCSCL) are shunted at output ports of the Gysel power divider to obtain NGD characteristics, and another resistor is shunted at the input port to realize perfect input and output matching. To verify the proposed structure, an NGD Gysel power divider is designed and fabricated. At the center frequency of 1.0 GHz, the measured NGD times for different output ports are −1.94 ns and −1.97 ns, the input/output port return loss is greater than 38 dB, the insertion loss is less than 8.3 dB, and the isolation between output ports is higher than 41 dB. To enhance the NGD bandwidth, two RCSCL networks having slightly different center frequencies are connected in parallel, which provides wider bandwidth with good input matching characteristics.

Group delay flatness and bandwidth enhancement of wideband negative group delay microwave circuit

Meng

Int J RF Microw Comput Aided Eng

Fang

et al. 2020

A wideband negative group delay (NGD) microwave circuit with group delay flatness and bandwidth enhancement is proposed. The proposed negative group delay circuit (NGDC) is composed of a resistor connected by two transmission lines and a parallel branch consisted of a resistor linking with a stepped-impedance transmission line and two open stubs. By tuning the characteristic impedance of the transmission lines, the flat-NGD bandwidth is enhanced. For verification, an NGDC with a size of 0.24λ g × 0.34λ g is designed, fabricated, and measured. The measurement shows that an NGD time of −0.5 ns at the center frequency of 1.0 GHz is obtained with the NGD bandwidth of 68.6% over 0.668 to 1.365 GHz. Also, the flat-NGD bandwidth reaches 46.3% or 0.776 to 1.243 GHz with ±8% group-delay fluctuation while the insertion loss is less than 18.8 dB and return loss is greater than 21 dB.