| 1. |
- Buisman, Koen, 1978, et al.
(författare)
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Mixed-Mode Active Load-Pull Using one Single-Ended Device-Under-Test
- 2021
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Ingår i: 2021 IEEE Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications, PAWR 2021. ; , s. 20-23
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Konferensbidrag (refereegranskat)abstract
- A method to emulate differential transmitter architectures is presented. The technique, which is based on mixed-mode active load-pull measurements, predicts power amplifier (PA) performance while avoiding the need to manufacture the complete PA. The method is based on an iterative procedure using transistor/branch PA active load-pull measurements together with the S-parameters of the load network. Advantageously, real world performance of the complete differential PA can be evaluated in the design stage. Thereby, many different output combiners and configurations, e.g., biases, transistors, and branch phases, can be fully evaluated without fabrication. Compared to prior art, the method requires only a single representative device-under-test, while providing flexibility in the input signal and the target load network. Thus, a novel powerful measurement tool for PA designers is presented. The technique is demonstrated by performing mixed-mode load-pull and emulating a differential amplifier at 2.14 GHz using continuous wave signals.
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| 2. |
- Carpenter, Sona, 1983, et al.
(författare)
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A D-Band 48-Gbit/s 64-QAM/QPSK Direct-Conversion I/Q Transceiver Chipset
- 2016
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 64:4, s. 1285-1296
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents design and characterization of single-chip 110–170-GHz ( -band) direct conversion in-phase/quadrature-phase (I/Q) transmitter (TX) and receiver (RX) monolithic microwave integrated circuits (MMICs), realized in a 250-nm indium phosphide (InP) double heterojunction bipolar transistor (DHBT) technology. The chipset is suitable for low-power ultrahigh-speed wireless communication and can be used in both homodyne and heterodyne architectures. The TX consists of an I/Q modulator, a frequency tripler, and a broadband three-stage power amplifier. It has single sideband (SSB) conversion gain of 25 dB and saturated output power of 9 dBm. The RX includes an I/Q demodulator with -band amplifier and 3 multiplier chain at the LO port. The RX provides a conversion gain of 26 dB and has noise figure of 9 dB. A 48-Gbit/s direct quadrature phase-shift keying (QPSK) data transmission using a 144-GHz millimeter-wave carrier signal is demonstrated with a bit error rate (BER) of 2.3 and energy efficiency of 7.44 pJ/bit. An 18-Gbit/s 64-quadrature amplitude modulation (QAM) signal was transmitted in heterodyne mode with measured TX-to-RX error vector magnitude (EVM) of less than 6.8% and spectrum efficiency of 3.6 bit/s/Hz. The TX and RX have dc power consumption of 165 and 192 mW, respectively. The chip area of each TX and RX circuit is 1.3mm by 0.9mm
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| 3. |
- Ghannam, Hedaia, et al.
(författare)
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Experimental Demonstration of Spectrally Efficient Frequency Division Multiplexing Transmissions at E-Band
- 2019
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 67:5, s. 1911-1923
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the design and the experimental demonstration of transmission of spectrally efficient frequency division multiplexing (SEFDM) signals, using a single 5-GHz channel, from 81 to 86 CHz in the E-hand frequency allocation. A purpose-built E-band SEFDM experimental demonstrator, consisting of transmitter and receiver GaAs microwave integrated circuits, along with a complete chain of digital signal processing is explained. Solutions are proposed to solve the channel and phase offset estimation and equalization issues, which arise from the well-known intercarrier interference between the SEFDM signal subcarriers. This paper shows the highest transmission rate of 12 Gb/s over a bandwidth varying between 2.67 to 4 CHz depending on the compression level of the SEFDM signals, which results in a spectral efficiency improvement by up to 50%, compared to the conventional orthogonal frequency division multiplexing modulation format.
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| 4. |
- Habibpour, Omid, 1979, et al.
(författare)
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Generation of multi-Gigabit/s OFDM signals at W-band with a graphene FET MMIC mixer
- 2017
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781509063604 ; , s. 1185-1187
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Konferensbidrag (refereegranskat)abstract
- This paper presents multi-Gigabit/s Orthogonal Frequency Division Multiplexing (OFDM) signal generation by using a graphene field effect transistor based resistive mixer at w-band. The OFDM signals consist of 64 subcarriers each carrying a quadrature-phase-shift-keying (QPSK) symbols. The results show that a bit error rate of 10 -4 is achievable for 8 Gbps data rate.
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| 5. |
- Hallberg, William, 1988, et al.
(författare)
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Emulation of Doherty Amplifiers Using Single- Amplifier Load-Pull Measurements
- 2020
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Ingår i: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 30:1, s. 47-49
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Tidskriftsartikel (refereegranskat)abstract
- A measurement-based approach for the analysis of Doherty power amplifiers (DPAs) is presented. The DPA behavior is emulated using an active load-pull setup, exciting a single device under test (DUT) in either of two states, corresponding to the main and auxiliary branches in a DPA. The dynamic loading condition in one state is determined from the Doherty combiner parameters and the knowledge of the DUT behavior in the other state. By iterating between these states, the measurements converge to the true behavior of a complete DPA. This method provides measurement-based insights in the dynamic loading conditions and the corresponding individual device performance without having to manufacture the full DPA. The method is demonstrated by emulating and cross-verifying a 2.14-GHz DPA.
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| 6. |
- He, Zhongxia Simon, 1984, et al.
(författare)
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A 15-Gb/s 8-PSK Demodulator With Comparator-Based Carrier Synchronization
- 2015
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 63:8, s. 2630-2637
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a novel 8-phase-shift-keying (8-PSK) carrier recovery and demodulation method using a comparator and frequency divider is proposed. A proof-of-concept 8-PSK demodulator for high-data-rate millimeter-wave communication systems is designed and tested, which can support 8-PSK transmission up to 15 Gb/s with a bit error rate less than 10-7
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| 7. |
- Nopchinda, Dhecha, 1991, et al.
(författare)
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8-PSK Upconverting Transmitter Using E-band Frequency Sextupler
- 2018
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Ingår i: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 28:2, s. 177-179
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Tidskriftsartikel (refereegranskat)abstract
- Operation of a frequency sextupler (X6) as a radio frequency (RF) E-band upconverting transmitter is experimentally demonstrated. An 8-phase-shift keying signal is digitally upconverted to 13.1-GHz intermediate frequency (IF). The resulting signal then goes through the X6 resulting in IF-to-RF upconversion to 78.6 GHz without the need for high-frequency oscillator, mixer, or modulator. A simple one-sixth phase retardation of the baseband signal is used as digital predistortion. A full signal processing chain is implemented at the digital receiver. Techniques to mitigate remaining nonlinearity and worsened phase noise are considered.
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| 8. |
- Nopchinda, Dhecha, 1991, et al.
(författare)
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An active load-pull technique creating time-variant impedances to emulate coupling between power amplifiers
- 2017
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Ingår i: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. ; , s. 1437-1440
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Konferensbidrag (refereegranskat)abstract
- A method for emulating antenna array coupling effects, based on active load-pull, to present time-varying impedances to power amplifiers is presented. An entire array, given identical elements, can be emulated using a single device-under-test. The method is demonstrated and verified by studying two scenarios, where the resulting adjacent channel power ratio and error-vector magnitude are given as function of delay and coupling for a 6W GaN power amplifier. Differences in adjacent channel power ratio and error-vector magnitude can be attributed to time-variant load impedances.
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| 9. |
- Nopchinda, Dhecha, 1991, et al.
(författare)
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Blind Receiver Distortion Compensation
- 2021
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Ingår i: 2021 51st European Microwave Conference, EuMC 2021. ; , s. 313-316
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Konferensbidrag (refereegranskat)abstract
- A novel technique to compensate for the nonlinearity of a receiver (RX) is proposed and demonstrated experimentally. The adaptive technique is fully blind and does not require any prior knowledge of the transmitting signal. The technique has the capability to both characterize and compensate for the nonlinearity of the RX, making it suitable for implementations in both communication and instrumentation systems. For the former, two RXs operating simultaneously and an attenuator are required to enable real-time data transmission. For the latter, measurements using a single RX and an attenuator can be done instead. By utilizing the knowledge of the signals received at different input power levels, the proposed technique provides improvements to the RX linearity. The technique is demonstrated experimentally with an RF amplifier, where significant improvements quantified through multiple indicators, e.g., the adjacent channel power ratio, are observed.
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| 10. |
- Nopchinda, Dhecha, 1991, et al.
(författare)
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Dual Polarization Coherent Optical Spectrally Efficient Frequency Division Multiplexing
- 2015
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Ingår i: IEEE Photonics Technology Letters. - 1041-1135 .- 1941-0174. ; 28:1, s. 83-86
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Tidskriftsartikel (refereegranskat)abstract
- A new optical spectrally efficient frequency division multiplexing technique, utilizing coherent detection and polarization division multiplexing, is proposed and demonstrated. The proposed system uses non-orthogonal and overlapping subcarriers to provide a significant reduction in both the electrical and optical bandwidth of up to 33%, relative to dual polarization orthogonal frequency division multiplexing (DP-OFDM), with an implementation penalty
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