An Exact Synthesis Method for Dual-Band Chebyshev Impedance Transformers

Abstract

Abstract-We propose an exact synthesis method which allows the design of dual-band transformers with an arbitrary even number of uniform sections giving equi-ripple impedance matching in two separate bands centered at two arbitrary frequencies. This method is a generalization of the exact Collin-Riblet synthesis of Chebyshev single-band transformers. As compared to a single-band Collin-Riblet transformer encompassing both required passbands, the proposed design yields significantly better performance in terms of passband tolerance and width.

Planar Transformers Excited by Square Waves

“…Also, it can be seen that the higher resonance peak voltage is found for transformer in configuration 10×800, this secondary turn number as the better gain performance in the transformer. Analyzing the worked configurations, we can see that when the secondary turn number increases beyond 800, the output voltage decreases quickly, because of the changes on coil parameters (parasitic capacitance, resistance and inductance), such that this step voltage response makes the frequencies ω 1 and ω 2 almost equal, which determines the difficulty in finding a frequency that satisfies the perfect crossing of peaks in accordance to (3). The aim of the analysis of these systems is to verify the possibilities of compact transformers in systems and new future applications of pulsed systems and air core transformers.…”

“…Developed researches about transformers, in the main cases, concern solenoids with sinusoidal excitation [1][2][3][4][5][6]. In some cases, several analyses about transformers built with planar coils [7][8][9][10][11] are found in literature, which generally is made in integrated circuits [12][13][14][15][16][17][18] and few in large dimensions (in the order of centimeters) with crossing of planar coils and ring coils excited by square waves [19][20][21].…”

A T-Section Dual-Band Matching Network for Frequency-Dependent Complex Loads Incorporating Coupled Line With Dc-Block Property Suitable for Dual-Band Transistor Amplifiers

“…Earlier reported distributed designs such as dual-band Chebyshev impedance transformer [10,11], dual frequency transformer [9] and two-section 1/3-wavelength transmission line based transformer [8] are extremely useful for matching real load and source impedances. However, these designs are not able to provide matching when the load impedances are complex and frequency-dependent as is the case with a generic dual-band amplifier where the transistor may possess two different complex impedances (Z L ) at two different frequencies as depicted in Figure 1(b).…”

A Novel Approach to the Design of Dual-Band Power Divider With Variable Power Dividing Ratio Based on Coupled-Lines

“…Many efforts have been made to develop more versatile dual-band components such as antennas [1][2][3][4], filters [5][6][7][8], coupler [9,10] and transformers [11,12]. Meanwhile, the power divider as one of the most important passive circuits has been widely used in microwave and communication systems.…”