Compact Filtering Power Divider Research Articles

A compact filtering power divider with low‐pass response and wide harmonic suppression

This article presents a miniaturized filtering power divider with low-pass behavior and a wide attenuation band. The proposed FPD has an operating frequency (fo) of 1.52 GHz with a relative stopband rejection of 165% and an electrical circuit size of (0.25λg × 0.14λg). The microstrip structure responsible for low-pass filter response is modeled using two rectangular-shaped open resonators (ORs) loaded with multiple sections of the interdigital capacitor. The low-pass filter operates at a cut-off frequency of 1.56 GHz and passband insertion loss of 0.35 dB. The output ports are connected with a 100 Ω isolation resistor to obtain good isolation in the passband. The two dissimilar defected ground structures are introduced in the ground plane for achieving circuit miniaturization and wide harmonic suppression up to 15 GHz. The electromagnetic simulated results of both the low-pass filter and FPD show a well-matched behavior with the experimental ones. The proposed FPD is suitable for GPS applications.

Filtering Power Divider With Tunable Attenuation Based on Graphene Nanoplates

A compact filtering power divider with tunable attenuation (FPDA) based on graphene nanoplates is proposed in this letter. The FPDA based on graphene nanoplates consists of three parts: the multimode resonant structure provides the field concentration and filter function, the divider structure generates the power distribution, and the graphene nanoplates loaded next to the resonator are responsible for the controllable adjustment of the concentrated electric field. Depending on the good cooperation of graphene and the filtering power divider, a novel FPDA with controllable attenuation is obtained. The measured results show that the tunable range can be tuned from −3 to −11 dB with a low reflection below −8 and 21 dB high isolation.

Compact filtering power divider using mixed quarter‐ and eighth‐mode substrate integrated waveguide resonant cavities with flexible design

In this paper, a series of filtering power dividers (FPDs) employing quarter-mode substrate integrated waveguide (QMSIW) and eighth-mode substrate integrated waveguide (EMSIW) resonant cavities have been first demonstrated. The proposed prototypes possess the merits of extremely miniaturized dimensions and relatively low insertion loss. Based on the detailed analysis and investigation of electromagnetic features and feeding types corresponding to the miniaturized SIW resonant cavities, two-order mixed QMSIW and EMSIW FPDs with electric coupling or magnetic coupling topologies are presented. In addition, multi-layered structures are implemented to decrease the footprints of the FPDs further. To attain a higher-order design and enhance the out-of-band rejection, a four-order multi-layered FPD with cross coupling mechanism is finally developed. For demonstration and verification, seven prototypes of the proposed FPDs operating at 4.8 GHz are meticulously designed, fabricated, and measured. All experimental results are in reasonable agreement with the simulated ones.

Compact Square Substrate Integrated Waveguide Filtering Power Divider With Wideband Isolation

In this letter, a new compact filtering power divider (FPD) on the square substrate integrated waveguide (SIW) with wideband isolation is proposed. As the isolation network is embedded in a square SIW cavity, good in-band isolation, compact structure, and low insertion loss can be simultaneously attained. The proposed FPD consists of the coplanar waveguide feeding line of Port 1, the capacitor, a resistor, and the square SIW cavity. TE101, TE201, and slot-line modes can realize third-order filtering response. Center frequency (f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ) and bandwidth of the filtering response can be independently adjusted. In order to achieve out-of-band isolation, Port 2/3 is placed in the specific position to suppress the high-order modes according to the electric-field distributions of these modes. Finally, a prototype with in-band return loss of 20 dB across 5.59-6.4 GHz is designed at 5.99 GHz. The bandwidths of isolation higher than 21 dB and upper stopband attenuation higher than 20 dB are extended to 2.79f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> and 2.83f <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , respectively.

Compact filtering power divider with extended stopband using out‐of‐phase feeding scheme

A compact filtering power divider is proposed with very wide stopband suppression in this letter. First, the dual-composite right- and left-handed (D-CRLH) resonator is employed, while one extended stopband can thus be achieved due to its inherently slow-wave response. Secondly, one out-of-phase feeding scheme is introduced to realise D-CRLH filtering power divider. By putting the input and output ports on the different sides of D-CRLH resonators, the mismatching can be realised for the harmonics below 10 GHz and wide stopband suppression is obtained accordingly. For experimental verification, a compact filtering power divider is designed, fabricated, and measured. Wide stopband suppression is observed until 5 f 0 without using bandstop structures or complex coupling topology.

Filtering power divider with harmonic suppression based on LTCC broadside coupling

A low-temperature co-fired ceramic (LTCC) filtering power divider with harmonic suppression is presented. It is composed of three resonators and one resistor. By using 3D technology, the two output resonators are symmetrically coupled to the input resonator to obtain the power splitting response. Each splitting path is composed of two resonators to achieve the filtering response. The resistor for isolation is located on the top layer and connected to the two output ports by vertical strips on the side walls. The broadside couplings between resonators produce required passband and stopband. A compact filtering power divider with the core size of 0.122λ g × 0.1λ g × 0.059λ g is implemented. Good filtering, power splitting and isolation performance are achieved. What is more, the second harmonic is successfully rejected below 20 dB without any extra circuit.

Compact filtering power divider with wide passband bandwidth

AbstractIn this article, a compact filtering power divider (PD) with wide passband bandwidth and high selectivity is designed and analyzed. The filtering PD is constructed by quarter‐ wavelength three‐conductor parallel‐coupled line structure terminated with two stepped impedance transmission line sections as well as an isolation resistor loaded on unique location. The even‐odd mode analysis is adopted to explain the operating mechanism of signal splitting, filtering, and isolating. Then, a practical design procedure is introduced. For verification, a wideband filtering PD centered at 3.0 GHz with a fractional bandwidth of 62% is designed and fabricated. The measured results agree well with the simulated ones.

Compact filtering power divider with harmonic suppression

This paper presents a compact power divider with wide-stopband bandpass responses. In the proposed circuit, two identical quarter-wavelength resonators are symmetrically coupled to a stub-loaded resonator to enable dual functions. Discriminating coupling is employed to suppress the third harmonic. By introducing series-connected two capacitors and one resistor, the isolation is enhanced to more than 20 dB. For demonstration, a filtering power divider operating at 2.4 GHz is designed and fabricated. Good agreement is observed between the measured and simulated results.

COMPACT FILTERING POWER DIVIDER BASED ON HALF MODE SUBSTRATE INTEGRATED WAVEGUIDE

In this paper, a compact filtering power divider (PD) based on half mode substrate integrated waveguide (HMSIW) is presented. The proposed structure is realized by etching slots on the top layer of the HMSIW PD. Accordingly, two resonators are embedded in each patch, as a second order filter. The slots dimensions are obtained by the relationship between them and the extracted external quality factor and coupling coefficient. A good agreement between the simulated and measured results is reported. The measured 3 dB fractional bandwidth is 25% (6.3-8.1 GHz). The maximum insertion loss is 0.9 dB, and the return loss is above 20 dB in the passband. This design has the advantages of low insertion loss, improved out-of-band rejection, compact size, controllable bandwidth, and high selectivity.

Compact filtering power divider with improved out‐of‐band performance

ABSTRACTA compact equal power divider (PD) with filtering function and improved out‐of‐band performance is proposed in this article. The proposed PD is based on the conventional Wilkinson PD and two filtering cells. The filtering cell is composed of four λ/4 stepped‐impedance resonators (SIRs). Using the edge and quasi‐lumped coupling topology, a compact PD with improving passband selectivity can be achieved. Meanwhile, by appropriately adjusting the impedance and electric length ratios of SIRs, the stopband can be extended to 39.2 GHz with a rejection level of 20 dB, which is 25 times of the fundamental frequency. The predicted results on S‐parameters are compared with the measured ones and good agreement is achieved. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2274–2277, 2015

Compact filtering power divider with high frequency selectivity and wide stopband using embedded dual‐mode resonator

A novel compact filtering power divider with high frequency selectivity and a wide stopband is proposed. The bandpass filtering response is implemented by using embedded dual-mode resonators. Source/load cross-coupling is used to improve the frequency selectivity of the passband. In addition, the even- and odd-mode method can be applied to analyse the proposed power divider. The presented filtering power divider has been designed, fabricated and measured. The measured results show reasonable agreement with the simulated ones.

Compact filtering power divider with good frequency selectivity and wide stopband based on composite right‐/left‐handed transmission lines

ABSTRACTA novel compact power divider with good frequency response and wide stopband based on composite right‐/left‐handed (CRLH) transmission line is presented in this article. To provide bandpass‐filtering frequency response, the bandpass filtering circuits is applied to this power divider using the CRLH resonators. The bandpass filtering circuit can generate two transmission zeros at the lower and upper stopband and have a wide upper stopband. Besides, the phase shift of the CRLH filter is tuned to be 90° for the sake of replacing the conventional quarter‐wave length branch line in the power divider. Moreover, the capacitive coupling between the input and output of the resonator is used simultaneously to generate three additional transmission zeros beside the passband edges. Then, the frequency selectivity of the power divider is greatly improved. A resistor is placed at the center of the symmetric plane to produce good isolation between the two outputs. A filter‐integrated power divider operating at 3.7 GHz is implemented. Good agreement between the simulated and measured results is observed. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2122–2125, 2014