Designing an Octave-Bandwidth doherty amplifier using a novel power combination method

2013-01-01
Sahan, Necip
Demir, Şimşek
In this paper, an octave bandwidth Doherty power amplifier (DPA) using a novel combiner is presented. The fundamental bandwidth limitation of the load modulation concept of a conventional Doherty structure is solved based on the proposed combination method. For verification, an octave bandwidth asymmetric Doherty architecture is implemented by using gallium-nitride (GaN) HEMT Cree CGH40010 and CGH40025 devices in the carrier and peaking amplifiers, respectively. The carrier and peaking amplifiers are designed to achieve optimal operation with 25Ω load and source impedances. The reduced load and source impedances simplify the matching circuits for broadband operation. Key building blocks, including the proposed combiner, carrier and peaking amplifiers as well as the 50/25 Ω input power divider, are outlined. The measurement results represent higher than 37% and 52% drain efficiencies in 6 dB load modulation region across the frequency range from 0.85 to 1.85 GHz and 0.90 to 1.60 GHz, respectively. The implemented Doherty amplifier represents acceptable linearity across the whole operation frequency range. In two-tone signal characterization, the implemented DPA performs with a drain efficiency of 55% and an inter-modulation distortion (IMD) of -30 dBc at an average output power of 41.2dBm at the center operation frequency of 1.35 GHz. In order to observe wideband signal characterization, a single carrier wideband code-division multiple access (W-CDMA) signal with a peak-to-average power ratio (PAPR) of 6.5 dB is applied and a drain efficiency of 51% with an adjacent-channel leakage ratio (ACLR) of -31 dBc is achieved at an average output power of 38.4 dBm.
Progress In Electromagnetics Research B

Suggestions

Design and fabrication of a detector logarithmic video amplifier
Dinç, Mustafa Barış; Yıldırım, Nevzat; Department of Electrical and Electronics Engineering (2011)
In this thesis a single stage detector logarithmic video amplifier is designed with a dynamic range of 40dB in 2-6GHz frequency band. Since the detector logarithmic video amplifier (DLVA) is used to convert the power of the RF signals to video voltages in logarithmic scale, it can be regarded as a logarithmic converter instead of logarithmic amplifier. The design is composed of two main parts: The Schottky diode detector rectifies the incoming RF signal and produces a video voltage and the logarithmic ampli...
A Wideband Fractal Antenna and Comparison of RF Rectifiers for Electromagnetic Energy Harvesting
Ozdemir, Huriye; Nesimoglu, Tayfun (2017-11-30)
This paper presents a wideband fractal antenna and compares two efficient rectifier topologies suitable for 2.45 GHz band. The combined fractal antenna and the rectifiers may be used for ambient RF energy harvesting from wireless LAN/Wi-Ei. The proposed fractal antenna covers the most frequently encountered frequency bands which are located around 1800 MHz, 2.1 GHz, 2.4 GHz and 2.45 GHz corresponding to standards like GSM/DCS, UMTS, ISM and WLAN respectively. The return loss of the proposed antenna is below...
AN AUTOMATIC MODE MATCHING SYSTEM FOR A HIGH Q-FACTOR MEMS GYROSCOPE USING A DECOUPLED PERTURBATION SIGNAL
Yesil, F.; Alper, S. E.; Akın, Tayfun (2015-06-25)
This paper reports a closed-loop controller system developed for in-run automatic matching of the drive and sense mode resonance frequencies of a MEMS gyroscope with a high quality factor (Q). This is achieved by injecting a perturbation signal to the quadrature cancellation loop, while keeping it decoupled from the angular rate control loop. The new controller is implemented in a CMOS ASIC together with the other sensor control loops, and it is verified to maintain matched-mode state under changing environ...
A Novel Characterization Method for MEMS Based Electrostatic Resonators for Q Enhancement and Feedthrough Current Elimination
AYDIN GÖL, EBRU; Kangul, M.; Gökce, Fuat; Zorlu, O.; Külah, Haluk (2016-11-03)
This paper introduces a new technique for electrostatic resonance characterization based on 2nd harmonic distortion terms at the output current. Mathematical analysis of the output current shows that the 2nd harmonic component exhibits higher quality factor (Q) than the 1st harmonic. Besides, output current to feedthrough current ratio is higher in the 2nd harmonic term. Experimental results show that the Q of the resonating system is enhanced by 66% with 2nd harmonic operation. Moreover, the resonance peak...
Design and Analysis of a Perfect Metamaterial Absorber for Sub-Terahertz Frequencies
Sabah, Cumali; Wellmann, Thorsten; Voss, Daniel; Zouaghi, Wissem; Roskos, Hartmut G. (2015-08-27)
A new near-perfect metamaterial absorber (MA) consisting of a square resonator with gaps and cross-wire strips is presented for the sub-terahertz frequency range. A narrow-band response of the proposed MA provides near-perfect absorption (absorbance of 99.23%) at 0.6 THz. In addition, numerical simulations show that the suggested MA could achieve very high absorption over a wide range of angles of incidence at least for transverse magnetic (TM) waves. As a result, the suggested model can be used for numerou...
Citation Formats
N. Sahan and Ş. Demir, “Designing an Octave-Bandwidth doherty amplifier using a novel power combination method,” Progress In Electromagnetics Research B, no. 56, pp. 327–346, 2013, Accessed: 00, 2022. [Online]. Available: https://hdl.handle.net/11511/95441.