Search

In this paper, the design of a wideband monolithic microwave integrated circuit (MMIC) low-noise amplifier (LNA) fabricated in 0.13- μ m GaAs pHEMT process is presented. A simple T-type input matching network (IMN) and a source feedback structure are employed to achieve low noise figure (NF). The MMIC LNA, which operates across 12–18 GHz, can be used for satellite applications. Experimental results show an NF around 1.5 dB in 12–17.5 GHz and a minimum NF of 1.21 dB at 16.5 GHz. In addition, a flat small-signal gain of 2 2 ± 0. 5 dB is achieved at 13.5–17.5 GHz. The input return loss is lower than − 1 0 dB at 12–14.5 GHz and the output return loss is lower than − 1 0 dB at 12–17 GHz. The power consumed is lower than 0.3 W and the P 1 dB (1-dB compression point) output power is around 13 dBm. [ABSTRACT FROM AUTHOR]

This paper introduces a methodology for implementing multi-band Doherty power amplifiers. Traditionally, a 90∘ impedance inverter line is required in Doherty architecture. In this contribution, a generalized impedance inverter line is utilized to construct multi-band Doherty power amplifiers. A tri-band Doherty power amplifier operating at 1.15, 1.85 and 2.55 GHz is designed to validate the proposed method. Measurement results show the fabricated Doherty power amplifier achieves 6 dB output back-off drain efficiencies of 62.3%, 49.3% and 50.5% at 1.15, 1.85 and 2.55 GHz, respectively. The peaking output power of the fabricated tri-band Doherty power amplifier is 43.2, 43.7 and 43.8 dBm with drain efficiencies of 64.5%, 62.2% and 64.5% at three working frequency points, respectively. Furthermore, when the designed Doherty power amplifier is driven by a 20 MHz wideband LTE signal with peak-to-average-power ratio of 6.4 dB, adjacent channel power ratios of − 29.4 and − 57.1 dBc are achieved before and after digital pre-distortion at 1.85 GHz. [ABSTRACT FROM AUTHOR]

A broadband low-noise amplifier (LNA) using 0.13 μ m GaAs HEMT technology for Ku-band applications is presented in this paper. By introducing an improved self-bias architecture, the LNA is achieved with low noise figure (NF) and high power gain. Compared with traditional LNA, self-bias architecture can reduce DC supplies to single one, and the improved architecture proposed here also takes part in source matching to reduce the complexity matching networks for broadband applications. To verify, an LNA operating over 12–18-GHz bandwidth is fabricated. The measurement results, for all the 72 chips on the wafer, and their average values are in great accordance with the simulation results, with 25.5–27.5-dB power gain, 1.1–1.8-dB NF, 15–17.5-dBm output power at P 1 dB and with a chip size of 2 mm ∗ 1.5 mm. [ABSTRACT FROM AUTHOR]

A parallel LβCα tank circuit with an α-order capacitor and a β-order inductor is proposed in this paper, where α and β are positive real numbers. The impedance of the parallel LβCα tank circuit, which could perform as a pure real, pure imaginary or short impedance, is discussed in detail, followed by the phase response analysis in α - β plane. The results show that the parallel LβCα tank circuit could act as a constant phase element. The resonance frequency analysis demonstrates that there exists more than one resonance frequency. And the time domain response expression of the proposed LβCα tank circuit is given by applying the inverse Laplace transform. The dual transformation relationship between the series and parallel LβCα tank circuit is summarized at last. [ABSTRACT FROM AUTHOR]