Duy P. Nguyen

A High Efficiency High Power Density Harmonic-Tuned Ka Band Stacked-FET GaAs Power Amplifier

A stacked-FET power amplifier (PA) with harmonic- tuned output matching network is demonstrated using a 0.15-μm Gallium Arsenide (GaAs) technology. The fabricated PA exhibits 28.5 dBm output power, 12 dB gain and 38.4% power added efficiency (PAE). To the best of our knowledge, this is for the first time stacked-FET technique is used in combining with harmonic-tuned output network to achieve high PAE and high power density simultaneously in a GaAs PA.

An Ultra Compact Watt-Level Ka-Band Stacked-FET Power Amplifier

An ultra-compact watt-level Ka-band monolithic microwave integrated circuit (MMIC) power amplifier (PA) is demonstrated using a 0.15 μm Gallium Arsenide (GaAs) stacked field effect transistor (stacked-FETs) configuration. The fabricated PA exhibits 31.5 dBm output power, 17 dB gain and 33% power added efficiency (PAE). The bandwidth is from 26 GHz to 31 GHz. The PA achieves 0.7 Watt/mm2 power density at 28 GHz. To the best of our knowledge, this PA achieves the highest power density among reported GaAs Ka-band PAs.

A K-Band High Power and High Isolation Stacked-FET Single Pole Double Throw MMIC Switch Using Resonating Capacitor

A K-band monolithic microwave integrated circuit (MMIC) transmit and receive (T/R) single pole double throw (SPDT) switch with low insertion loss, high isolation and ultrahigh output power is demonstrated using 0.15-μm Gallium Arsenide (GaAs) technology. A shunt field effect transistor (FET) configuration is used to provide low insertion loss and high isolation while the stacked-FET is employed to improve power handling capability. The novel GaAs switch exhibits a minimum measured insertion loss of 1.4 dB and less than 2.5 dB from 22 GHz to 26 GHz as well as 44 dB isolation. The measured input 1-dB power compression point (P1 dB) exceeds 4 W.

A compact 29% PAE at 6 dB power back-off E-mode GaAs pHEMT MMIC Doherty power amplifier at Ka-band

In this paper, we present a compact Doherty power amplifier (DPA) in a 0.15-μm enhancement mode (E-mode) Gallium Arsenide (GaAs) pseudomorphic high electron mobility transistor (pHEMT) process at Ka-band. The 2-stage DPA uses an integrated input broadside coupler to miniaturize the die size to 2.86 mm2. The monolithic millimeter-wave integrated circuit (MMIC) DPA exhibits a measured output power of 26 dBm and a measured average gain of 12 dB. The gain bandwidth covers from 25.5 to 33 GHz. The measured peak power added efficiency (PAE) is 40% and the PAE at 6 dB output power back-off is 29%. Moreover, an adjacent channel power ratio (ACPR) of −45 dBc has been measured using a 20 MHz digitally modulated signal and digital predistortion (DPD).

A Ka-band asymmetrical stacked-FET MMIC Doherty power amplifier

We present a stacked-FET monolithic millimeter-wave (mmW) integrated circuit Doherty power amplifier (DPA). The DPA employs a novel asymmetrical stack gate bias to achieve high power and high efficiency at 6-dB power back-off (PBO). The circuit is fabricated in a 0.15-µm enhancement mode (E-mode) Gallium Arsenide (GaAs) process. Experimental results demonstrate output power at 1-dB gain compression (P1dB) of 28.2 dBm, peak power added efficiency (PAE) of 37% and PAE at 6-dB PBO of 27% at 28 GHz. Measured small signal gain is 15 dB while the 3-dB bandwidth covers from 25.5 to 29.5 GHz. Using digital predistortion (DPD) with a 20 MHz 64 QAM modulated signal, an adjacent channel power ratio (ACPR) of −46 dBc has been observed.

High efficiency power amplifiers for 5G wireless communications

We present several design techniques to achieve high efficiency and linear power amplifiers in the millimeterwave frequencies. We will first review the performance of power amplifiers in different semiconductor process technologies at millimeter-wave frequencies. We will discuss the design, implementation and performance of stacked-FET power amplifiers, Doherty power amplifiers and linearization techniques to achieve high efficiency and linearity in millimeter-wave frequencies. The presented power amplifiers have applications in the 5G wireless communications.

High dynamic range X-band MMIC VGLNA for transmit/receive module

In this paper, a monolithic variable gain low noise amplifier (VGLNA) for transmit/receive module is presented. The voltage controlled attenuator (VCA) in the VGLNA helps to control the gain of the LNA for 20 dB range. This core-chip achieves a high dynamic range with the measured minimum Noise Figure (NF) of 1.2 dB and OIP3 of 29 dBm at 9 GHz. The operating bandwidth of this chip is from 7.5 GHz to 10.5 GHz. Within this band, the chip has the NF lower than 1.5 dB, the gain higher than 24 dB and the OIP3 better than 25 dBm. The 1 dB compression point is 14 dBm at the output.

A 14–31 GHz 1.25 dB NF enhancement mode GaAs pHEMT low noise amplifier

In this paper, we report a wide bandwidth low noise amplifier (LNA) fabricated in a 0.15 μm enhancement mode (Emode) gallium arsenide (GaAs) pseudomorphic high electron mobility transistor (pHEMT) process. The lna employs source degeneration along with a resistive feedback network to achieve low noise figure (NF) over a wide bandwidth. Experimental results show that the LNA exhibits a maximum gain of 30 dB and maintains higher than 25 dB from 14 to 31 GHz. The measured minimum NF is 1.25 dB along with 17.5 dBm output 1-dB compression point (OP1dB) and 28.5 dBm output 3rd order intercept point (OIP3).

High Power Monolithic pHemt GaAs Limiter for T/R Module

In this paper, a high power monolithic GaAs limiter for transmit/receive module is presented. While keeping the output power below 100 mW (20 dBm), this limiter can sustain a RF input power up to 4 Watts (36 dBm). The survival input power of this limiter can get up to 10 Watts (40 dBm). This chip obtains a wide bandwidth from 7 to 21 GHz. Within this band, the chip has the insertion loss lower than 2.3 dB and achieves only 1 dB insertion loss in the X-Band from 7 GHz to 12 GHz.