Gysel Power Divider Research Articles

Dual‐band Gysel power dividers with large frequency ratio and unequal power division

In this article, a dual-band Gysel power divider is proposed based on the topology of finite-ground microstrip line. The general design method for the large frequency ratio and unequal power division is derived and the detailed design rules are provided. It is shown that the frequency ratio can be achieved from 1 to 10, and the power division ratio of each frequency band can be separately determined. Moreover, the phase differences at two operating bands could be designed to be either in-phase or out-of-phase. Finally, two prototypes are designed, implemented, and experimented to validate this proposal. The measured results of the first design show the frequency ratio of 4 with power division ratios of 2:1 in both passband, while the second example is designed with the frequency ratio of 10 with power division ratios of 2:1 and 1:1 in the first and second passband, respectively. Both results show a good agreement between the simulated and measured results.

Notice of Retraction: Comments on “A Modified Gysel Power Divider of Arbitrary Power Ratio and Real Termination Impedances”

Without fully understanding the previous works of asymmetric ring hybrids terminated in arbitrary real impedances, it is insisted that the Gysel power dividers terminated in arbitrary real impedances should be first reported in the above article. However, the claim does not seem to be correct. The misinterpreted concept will be clarified.

Generalized high‐isolation n‐way Gysel power divider with arbitrary power ratio and different real terminated impedances

An exact closed-form design approach for a generalized high-power n-way Gysel power divider is proposed. The power divider could be designed to achieve an arbitrary power ratio with the flexible multiway application, arbitrary real terminated impedance, excellent isolation, and easy fabrication through both planar and three-dimensional structures. Moreover, this improved power divider could maintain high power processing capacity through the coaxial cavity transmission line and grounding resistances. The exact analytical solutions related to ideal port matching and high isolation are obtained based on the circuit and transmission-line theory. To verify the proposed approach, a compact 3-way coaxial power divider with a pre-designed power ratio of 1:1.5:2 and four different real terminated impedances of 50, 55, 60, and 65 Ω is designed and fabricated. Excellent agreement is achieved between the simulated and measured results. Measurements from 4.7 to 5.7 GHz show that the return losses of all input and output ports are better than 15 dB. The maximum insertion loss is 0.5 dB, and the phase imbalance is approximately less than 6.1°. In addition, the isolation between any two output ports is better than 23 dB from 4.5 to 6 GHz. Meanwhile, the power handling capability can reach the maximum power of the commercial 50 Ω SMA connectors (2.098 kW).

A compact Gysel power divider design using U-shaped and T-shaped resonators with harmonics suppression

ABSTRACTIn this paper, design process of a new compact microstrip Gysel power divider (GPD) with harmonics elimination is proposed. In the designed GPD structure, two types of resonators are applied to make transmission zeros (TZs). T-shaped resonator makes one TZ at lower frequency and U-shaped resonator makes two TZs at higher frequencies. These three created transmission zeroes by applied resonators result in the good harmonics suppressing in the Gysel divider. The LC-equivalent circuit (LCEC) of the resonators is extracted and the locations of these three transmission zeroes are calculated analytically. The proposed GPD creates three transmission zeros at near 3 GHz, 4.9 GHz, and 9.1 GHz. The proposed Gysel power divider (GPD) with applied resonators reduces the circuit size more than 66% (occupied 34% size) compared with the conventional GPD with λ/4 transmission lines. Moreover, the fractional bandwidth of the proposed divider is 50% and also suppresses up to seventh harmonic.

Novel Gysel Power Dividers with Negative Group Delay Characteristics

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.

Dual-Band Gysel Power Divider With Different Power Dividing Ratios

This letter presents a dual-band Gysel power divider (PD) with different power dividing ratios. Unlike traditional dual-band Gysel PDs, the power dividing ratios of proposed PD are determined by both electrical lengths and characteristic impedance of transmission lines. The proposed circuit is analyzed based on transmission line theory and design equations are derived. For illustration, a prototype operating at 1 and 2 GHz is designed and measured. The concept has been verified by the measured results.

A Circularly Polarized High-Gain Planar 2 × 2 Dipole-Array Antenna Fed by a 4-Way Gysel Power Divider for WLAN Applications

In this letter, a circularly polarized high-gain planar 2 × 2 dipole-array antenna for wireless local area networks, radio frequency identification, radar, and satellite communication applications is proposed. The proposed array antenna consists of four planar dipole antennas with integrated microstrip-to-parallel-stripline linear tapered balun and feeding network. The designed array antenna is fed by a modified 4-way Gysel power divider. The proposed antenna uses three stacked metal layers, and a metal reflector under the antenna boosts the overall antenna gain. The size of the designed antenna on 3.2 mm thick FR4 substrate was 150 mm × 150 mm × 20 mm including the reflector. The designed antenna had left-hand circular polarization (LHCP), and its measured LHCP gain value was 8.70–9.62 dBic at 2.4–2.6 GHz band. The measured axial ratio was 0.3–2.2 dB at the same frequency band of interest. A thorough theoretical analysis and design equations of the proposed array antenna are presented in this letter.

A size reduced Gysel power divider with simple structure and high design flexibility

AbstractIn this letter, a new simple structure of Gysel power divider (PD) is proposed. Comparing to the conventional Gysel PD, the high‐power handling capability is reserved with size reduction from the nonlinear relationship between the phase delay and the physical dimension of the utilized open‐circuited coupled line. The structure is analyzed according to an open‐end‐stub‐based equivalent circuit, in which procedure the closed‐form design equations are derived simultaneously. Also, the analysis shows a high design freedom in choosing the values of the isolation resistors and the impedances of the utilized transmission lines (TLs), which property can be used to control the bandwidth (isolation and input return loss band) of the proposed structure. Finally, in order to verify the proposed design theory, a Gysel PD with a center frequency of 2.5 GHz is designed, simulated, fabricated, and characterized. Besides good agreement with the simulation data, the experimental results show that the proposed PD features a wide isolation band which is around 89% with the reference of 15‐dB loss.

<inline-formula> <tex-math notation="LaTeX">$N$ </tex-math> </inline-formula>-Way Gysel Power Divider With Arbitrary Power-Dividing Ratio

In this paper, N-way Gysel power dividers with arbitrary power-dividing ratio are studied by using node voltage and current method for the first time. Closed-form analytical equations are derived for the design of the proposed Gysel power divider with arbitrary power division on arbitrary terminated impedance. Parameters that might influence the frequency bandwidth are investigated and optimized to achieve balanced performance. For verification, 3-way and 6-way Gysel power dividers are, respectively, designed, fabricated, and measured at a center frequency of 3.45 GHz, with dividing ratio 1:1:1, 1:2:3, 1:1:1:1:1:1:1, and 1:1.2:1.2:1.5:1.5:2, respectively. Good agreements can be observed among expected, simulated, and measured results, indicating the validity of the proposed strategies.

In-Phase T-Junction: Study and Application to Gysel Power Dividers for High Power-Division Ratios Requiring No High-Impedance Transmission-Line Section

A novel Gysel power divider, which can be fabricated without a need for any high-impedance transmission-line section (TL), even for the power-division ratios higher than 15 dB, is presented. To derive its design formulas, a new study on the conventional in-phase T-junctions is carried out, and two conditions are newly derived for the arbitrary power-division ratios and perfect matching at all the ports, which can be applied for any symmetric or asymmetric Gysel power divider without any additional effort to design the isolation circuit. As a proof-of-concept demonstration, two prototypes I and II at the design frequency of 1 GHz are fabricated for the power-division ratios of 17 and 20 dB, respectively. Such power-division ratios have never been tried before not only for the Gysel power dividers but also for generic planar power divider topologies without the use of high-impedance TLs for the wider bandwidths. The measured results are in good agreement with the predictions.

Design of Compact Tri-Band Gysel Power Divider With Zero-Degree Composite Right-/Left-Hand Transmission Lines

In this paper, a tri-band Gysel power divider (PD) based on zero-degree composite right-/left-handed (CRLH) transmission lines (TLs) is presented. Compared to the generalized design methods in which multiple passbands are realized by replacing conventional impedance transformers with quarter-wavelength CRLH-TLs, the employed zero-degree CRLH-TLs include high design flexibility for the characteristic impedance and phase responses of the composed left-handed and right-handed TLs, which can be used to separately control the bandwidths of the three passbands. In addition, the microstrip-to-slotline transition is utilized to replace the conventional 180° TL, which can expand the realizable range of the three center frequencies and reduce the circuit size, as well. The proposed theory is validated using two designs: One involves a broadband PD with a center frequency of 2.5 GHz, while the other is a tri-band PD centered at 3.5 GHz, 2.5 GHz, and 1.5 GHz. Good agreement between the simulated and measured results are obtained; for the first PD, a fractional 3-dB bandwidth of up to 116% is achieved, whereas, for the tri-band PD, a size reduction of 80% is achieved with good impedance matching and isolation performance.

Equal and unequal quad‐band Gysel power dividers

This article presents for the first time a quad-band Gysel power divider capable of achieving equal and unequal power division at four arbitrary frequencies. The structure of the proposed divider is similar to its single-band counterpart but loaded with quad-band reactive networks. The design procedure and theoretical analysis of the proposed divider are presented. A quad-band Gysel power divider with equal division and another with 2:1 unequal division are designed at the operational frequencies of 0.85, 1.6, 2.4, and 3 GHz. Simulation and measurement results of the two dividers are presented, and good performance is observed at each band. For both designs, the realized power division ratios are within 1 dB from their ideal values, whereas the matching and isolation levels are below −10 dB at the four bands.

Quad‐band Gysel power divider based on coupled lines

A quad-band Gysel power divider based on the coupled-line network is proposed. The closed-form equations are derived to solve even- and odd-mode impedances of the coupled lines. For illustration, a prototype operating at 0.6, 1.41, 2.14 and 2.95 GHz is designed and fabricated. The measured results show a good agreement with the simulated ones.

Miniaturized Gysel power divider with nth harmonics suppression

In this paper, a miniaturized Gysel power divider with nth harmonic suppression has been presented. The Gysel power divider retains its capability of high-power handling, while extreme size reduction makes it suitable for application in small-sized circuits with higher order harmonics rejection. A lowpass filter with high performance and appropriate characteristic has been placed instead of the conventional transmission lines a quarter wavelength. It results in the size reduction and harmonics rejection of the Gysel power divider, effectively. The presented Gysel power divider operated at center frequency of 0.764 GHz with fractional bandwidth of 36%. To substantiate the validity and efficiency of the proposed circuits, the designed power divider was fabricated and measured. It is seen that the results of the measurements and simulations are highly consistent together. The main frequency; the return loss of the port 1, the return loss of the port 2, isolation, and insertion loss are 28, 29, 32 and 1.3 dB, respectively. The overall circuit size is 22.1 mm × 65.7 mm.

GaN‐HEMT asymmetric three‐way Doherty power amplifier using GPD

A gallium-nitride high electron mobility transistor (GaN-HEMT) three-way asymmetric Doherty power amplifier using an unequal three-way Gysel power divider (GPD) is presented in this study. Considering the output power capacity of transistors, the peaking amplifier was designed to have an output power capacity that is 1.5 times larger than that of the carrier amplifier through the use of a parallel combination of two different power amplifiers. A peaking amplifier that is 1.5 times larger can provide a back-off level of 7.5 dB for another peak efficiency. Two different power amplifiers in the peaking amplifier can work as a single power amplifier through an optimization of the input power division ratio (PDR). To split the input power for the carrier and the two peaking amplifiers, an unequal three-way GPD with an optimized PDR was employed. The implemented Doherty power amplifier for the 2.14 GHz band exhibited a drain efficiency (DE) of 59.5% and an adjacent channel leakage ratio (ACLR) of 27.1 dBc at an average output power of 37.2 dBm (7.2 dB for the output power back-off) for the 2.14 GHz downlink long-term evolution signal, which has a peak-to-average power ratio of 6.5 dB and a signal bandwidth of 10 MHz.

Ka-Band Rectangular-Waveguide Gysel Power Divider with Low Insertion Loss and High Output Isolation

A Ka-band Gysel power divider based on rectangular waveguide is presented in this paper. The model and equivalent circuit of the presented power divider is introduced. The even- and odd-mode analytical method is applied to analyze the equivalent circuit. A Ka-band waveguide Gysel power divider is designed, optimized, fabricated, and measured. Good agreement between the simulated and measured results is demonstrated. The measured average insertion loss is approximately 0.25 dB from 30 to 34 GHz. The measured output isolation in the same frequency band is greater than 15 dB.

Wideband Gysel HMSIW power divider with high power-handling capability

AbstractA novel Gysel power divider with high power-handling capability based on half-mode substrate integrated waveguide (HMSIW) has been presented in this paper. A HMSIW ring is used and good input/output impedance matching is achieved based on HMSIW-microstrip taper transition. Two microstrip stubs are introduced in HMSIW ring to assemble two isolation resistors to improve the isolation between the output ports. The even- and odd-mode analysis method is used for the presented circuit. A prototype of the presented power divider is designed, fabricated, and measured. The measured results show a reasonable agreement with the simulated ones.

Gysel power divider with efficient second and third harmonic suppression using one resistor

A Gysel power divider/combiner with the second and third harmonic suppression using one resistor is proposed. Three open-circuit stubs are used to suppress the second and third harmonics. To calculate the values of the design parameters, the closed-form design equations are derived. A sample power divider is designed at 1 GHz to verify the design procedure. The measured results are nearly in agreement with the simulation results. The proposed Gysel power divider provides a high power-handling advantage over Wilkinson power divider. Moreover, it has a fractional bandwidth of 30% and harmonic suppression of 25 and 35 dB at the second and third harmonics, respectively.

Frequency-dependent behavioral-model-based nonlinear analysis and design of a low-profile transmit active phased array antenna

Design and behavioral-model-based nonlinear analysis of a 3-GHz active-phased array antenna (APAA) are presented. Four nonlinear power amplifiers are employed in the output ports of the feeding network (FN) and analyzed based on a 5-order polynomial model with frequency-dependent coefficients. The FN is based on 4-port new Gysel power dividers and combiners arranged in such a way to feed the array with Gaussian-like amplitude and in-phase distributions. Beam steering capability is obtained in 2 directions by a new technique including a phase shifter and an amplitude controller (AC). The features result in a low-profile APAA whose design and fabrication complexity and cost are reduced. Single and 2-tone power tests are performed to develop analytical expressions in nonlinear region for array factor as a function of the model, FN and the phase and ACs. A similar system with frequency-independent model is also analyzed for comparison in terms of scan loss, beamwidth, side-lobe level, beam position, and gain. A microstrip array antenna including the power amplifiers, pre-amplifiers, AC, delay-line-based phase shifters and Gysels is fabricated and measured. The simulation results at the single and dual tones and the intermodulation products are presented which have a good agreement with the measurements.

Corrections to “Gysel Power Divider With Arbitrary Power Ratios and Filtering Responses Using Coupling Structure” [Mar 14 431-440

Corrections to “Gysel Power Divider With Arbitrary Power Ratios and Filtering Responses Using Coupling Structure” [Mar 14 431-440