| Title |
Harmonic Rejection in Wideband Power Amplifier Using Switch Filter Module |
| Authors |
Young-Lak Kim ; Chun-Hyung Cho |
| DOI |
http://doi.org/10.5207/JIEIE.2025.39.2.113 |
| Keywords |
Broadband communication system; Channel filter; Harmonic of power amplifier; Pin diode switch |
| Abstract |
In modern society, high-speed transmission of large amounts of information is possible through broadband communication networks, but the use of broadband communication systems inevitably leads to problems of cross-channel interference and noise. In this study, we showed that RF harmonic signals can be dramatically removed using a broadband high-power multi-switch filter module to minimize interference in adjacent bands that commonly occurs in broadband communication systems. The overall design consists of a broadband RF switch design and an RF channel filter design to remove RF harmonic signals. Note that 8 channel filters were designed to remove harmonics in a wide band of 30∼512MHz. We then connected it to a UVHF power amplifier and measured the generated harmonics and observed that the out-of-band suppression amount was in the range of ?60∼-80dB, which is better than the out-of-band suppression amount(-50∼-60dBc or less), the insertion loss was at least 0.5dB or less, and the return loss was at least 20dB or less. In addition, the first harmonic measured from the power amplifier was in the range of -71 to -77dBc, and the second harmonic was in the range of ?74∼-77dB. That is, the harmonic values f or all channels were below ?71∼-77dBc, which is approximately 11dBc lower than the standard target value of -60dBc, which demonstrated that there was an significant improvement of about 17dBc when using our proposed design. |