Wideband Filtering Power Divider Research Articles

A wideband filtering power divider with improved out-of-band suppression

A wideband filtering power divider with improved out-of-band suppression

Novel 6‐GHz/80.8% fractional bandwidth filtering power divider with ultra‐large coupling coefficient using air‐dielectric broadside‐coupled lines

AbstractIn the letter, a wideband filtering power divider (FPD) with ultra‐large coupling coefficient using air‐dielectric broadside‐coupled lines is proposed. The broadside‐coupled line and single transmission line are alternately connected to construct three resonators, which can be used for large bandwidth and high selectivity filtering. An improved substrate‐integrated suspended line (SISL) structure with two inner layers is developed. In the structure, the broadside coupling occurs by the air. The overall structure is implemented based on the low‐cost FR4 dielectric material. The designed FPD is simulated and fabricated. The results demonstrate its excellent performance, with center frequency of 6 GHz, a fractional bandwidth (FBW) of 80.8%, a maximum coupling coefficient of 0.84, an insertion loss of less than 0.29 dB, and an out‐of‐band rejection of more than 52 dB.

Wideband Filtering Power Divider With Unequal Power Division Ratio and All-Frequency Input Absorptive Feature

Wideband Filtering Power Divider With Unequal Power Division Ratio and All-Frequency Input Absorptive Feature

Design of a four‐way out‐of‐phase wideband filtering power divider with high selectively response

This paper proposes a four-way out-of-phase wideband filtering power divider (OWFPD). By introducing a multiport out-of-phase topology, and a pair of multimode U-shape slotline resonators, satisfactory wideband out-of-phase filtering power division responses can be easily achieved. Owing to the different standing wave distribution of the slotline, adjacent out ports can exhibit out-of-phase characteristic. In the meantime, decent port-to-port isolations are attained with the developed isolation network. Thoroughly theoretical theory and design procedure are provided to explore the operation and guide the multiway OWFPD design. For validation, one prototype is implemented. Results indicate that the new four-way OWFPD exhibits compact size, sharp roll-off, good in-band isolations as well as nice phase and magnitude imbalance.

Wideband and compact filtering power divider based on vertically installed planar structures

In this article, a wideband filtering power divider using vertically installed planar (VIP) circuit is proposed, where three-line coupled structures are introduced to realize filtering responses. The even-odd mode analysis method is applied to assess the electrical performance of the whole structure. The simulated and measured results demonstrate that the proposed design has a wide operation bandwidth (>103%), low insertion loss (<0.6 dB) and good isolation (>15.2 dB). Moreover, the amplitude imbalance and phase imbalance are less than 0.2 dB and 0.5°, respectively.

A new wideband filtering power divider with ultra‐wide stopband using microstrip/slotline transitions

In this article, a wideband filtering power divider (FPD) is proposed based on a new design scheme originating from the microstrip/slotline broadside-coupled structure. It is simply composed of one microstrip T-junction and two transmission lines on the top layer, and a pair of U-shape slotline resonators as well as one isolation resistor-loaded slotline stub with a circular slot terminal in the ground plane. The presented FPD stands out by much wider bandwidth, improved performance, and simple design layout. For verification, one prototype FPD is designed and fabricated with a center frequency of 4.0 GHz and a fractional bandwidth of 77.1%. Simulated results coincide well with the measured ones. Results indicate that the new wideband FPD exhibits not only a simple layout without additional loading elements, but also nice port-to-port isolation over a whole wide frequency band range, good return losses, and 20-dB harmonic suppression up to (2.5 f0).

A 3.9GHz/63.6% FBW Multi-Mode Filtering Power Divider Using Self-Packaged SISL

In this brief, a self-packaged substrate integrated suspended line filtering power divider with wideband and high frequency selectivity by using coupled-line termination added multi-mode resonator has been developed, and has been demonstrated by experiment. Three transmission zeros have been realized due to the coupled-line termination loaded stepped impedance resonator and multi-mode resonator, which improve the frequency selectivity and out-of-band suppression importantly. The wideband filtering power divider has a measured center frequency of 3.9GHz, a fractional bandwidth of 63.6%, an insertion loss of 0.74dB, an in-band isolation (S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">23</sub> ) of no less than 18.3dB, and an out-of-band rejection of more than 40dB.

Wideband filtering power divider with wide rejection bandwidth and isolation

A wideband filtering power divider (FPD) with wide rejection bandwidth and good isolation is presented, based on conventional Wilkinson structure. Parallel coupled lines and two pairs of open-circuit stubs are used for achieving bandpass filtering response and enhancing the performance of the rejection bandwidth. Furthermore, by properly choosing two resistors between two pairs of open-circuit stubs allows good isolation performance. Measured results indicate that the FPD operates at 2.35 GHz ( f 0 ) with a − 20 dB bandwidth of 55.3%. In the upper stopband range from 3.7 to 8.8 GHz (3.74 f 0 ), the minimum rejection is 20 dB. Within working band, the isolation between the output ports is higher than 24 dB. In addition, ultra-wide isolation better than 20 dB from DC to 10 GHz is obtained.

Design of a wideband filtering power divider with good in‐band and out‐of‐band isolations

In this article, a wideband filtering power divider with good in-band and out-of-band isolations is designed based on a hybrid Wilkinson and Gysel structure. To achieve a good in-band response, two additional in-band transmission poles can be introduced by installing the coupled-line structures at each port. By mounting a stepped impedance open stub at the input port, two transmission zeros are generated near the passband to improve the passband skirt. Furthermore, the out-of-band rejection and isolation are achieved by the other two transmission zeros, which are produced by the open stub and the three coupled-line sections mentioned above. Additionally, a good in-band isolation is realized by the isolation resistor between output ports. For the demonstration, a wideband filtering power divider centered at 1.5 GHz with a 56% fractional bandwidth and 20-dB isolation is designed and fabricated. The simulated and measured results are in good agreement with each other.

Novel Wideband Microstrip Filtering Power Divider Using Multiple Resistors for Port Isolation

In this paper, a novel wideband filtering power divider with third-order quasi-Elliptic bandpass response is proposed. Its physical mechanism is revealed by the lumped-element equivalent circuit, such as how its transmission poles and zeros are formed. The design of the proposed filtering power divider can be simplified as its even-mode model can be synthesized by conventional filter synthesis technique, and then the initial structure parameters can be analytically determined. Owing to the fact that as many as three resistors are joined, high isolation can be achieved between two output ports. To demonstrate its good performance, an example was designed, fabricated, and measured, whose center frequency is 1.99 GHz and 3-dB fractional bandwidth is 43.7%. Moreover, as great as 34 and 28 dB out-of-band suppression can be achieved in the lower and upper stopbands, respectively. The isolation between two output ports is better than 20 dB for a wide frequency range.

High‐performance filtering power divider with multiple transmission zeros

AbstractA wideband filtering power divider (FPD) with multiple transmission zeros (TZs) is presented in this article. By introducing four pairs of coupled lines and two half‐wavelength stubs to the power divider, a flat passband with two controllable TZs and four fixed ones is achieved. A resistor is then arranged in the structures to obtain good isolation between output ports. For demonstration, a FPD centred at 2.6 GHz with 3‐dB fractional bandwidth of 22% is designed, fabricated, and measured. The measured minimum in‐band insertion loss is 0.34 dB, and the isolation is over 20 dB within the passband. Good agreement between the simulated and measured results can be observed.

Wideband filtering power divider with deep and wide stopband

AbstractIn this study, wideband bandpass power divider with good out-of-band performance is proposed. Two bandpass filters (BPFs) are utilized to substitute the quarter-wavelength transmission line in conventional Wilkinson power divider. A resistor is specially arranged between two BPFs for a good isolation. Four transmission zeros (TZs) are found to be distributed in the lower and upper stopband of the power divider. Moreover, the locations of two TZs can be shifted by tuning the impedance ratio of the center-loaded open stub, which is propitious to improve the frequency selectivity. Even- and odd-mode methods are applied to analyze the proposed power divider and closed-form design formulas are obtained. Finally, two prototype power dividers with measured rejection level in the upper stopband larger than 29.1 and 32 dB till to 2.7f0 and 2.69f0, respectively, are designed and fabricated to testify the proposed design concept. Good agreement between the simulated and measured results is observed, validating the validity of the proposed design principle.

Wideband Filtering Power Divider With Ultra-Wideband Harmonic Suppression and Isolation

In this paper, a wideband filtering power divider (PD) with ultra-wideband harmonic suppression and isolation is proposed. The dual coupled-line sections are embedded to the conventional quarter-wavelength transmission lines, which helps to extend the passband of the PD. With the introduction of the short-circuit stubs shunted at the output ports and the coupled lines with the open-circuit stubs, the ultra-wide stopband can be implemented more efficiently, thus resulting in five transmission zeros from 2 to 6 GHz. Furthermore, the improved isolation structure with series connected a resistor and a capacitor can be utilized to realize the ultra-wide isolation frequency band. Using a single resistor between two output ports, we have achieved an excellent in-band isolation. For demonstration, a wideband filtering PD operating at 1 GHz with a 20-dB bandwidth of 50% and an ultra-wide stopband better than 20 dB from 2 to 6 GHz is designed, fabricated, and measured. The measured results agree well with the anticipation.

Wideband filtering power divider with high selectivity

A wideband filtering power divider (PD) with high selectivity is introduced, based on a terminated coupled line structure. The bandwidth tuning, isolation and impedance matching performances optimisation are presented and explained. Finally, the filtering PD is designed and implemented with a centre frequency (f 0) of 3.0 GHz and a fractional bandwidth of 70%. The upper stopband is achieved up to 2.6 f 0, with a rejection of better than 13 dB. The measured minimum in-band insertion loss is 0.3 dB (not including the splitting loss). Isolation of higher than 16.7 dB between the output ports is observed up to 2.7 f 0.