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With the growing interest in millimeter-wave (mmW) communication links, especially for multi-gigabit backhaul applications, detailed studies on the performance limits in terms of achievable transmission distance and data rate, but also, and perhaps even more important, thorough investigations on the influence of different weather conditions gain in importance. In this paper we present a millimeter-wave monolithic integrated circuit (MMIC)-based transmit and receive front-end and ultra-broadband wireless data transmission experiments utilizing a 240 GHz carrier frequency in a long-range outdoor scenario as well as measurements inside a climatic wind tunnel. Data rates up to 64 Gb/s and various complex modulation formats are employed. While in the outdoor transmission, the link is tested in terms of maximum achievable transmission distance and data rate as well as alignment accuracy, in the climatic wind tunnel the influence of rain and fog in the transmission path is investigated in a defined and controlled environment.

This paper presents the influence of bandwidth-dependent deterministic impairments of diplexer filters on the performance of an E-band wireless link. The degradation of performance due to group delay variation and amplitude ripple in the analog front-end transmission chain is considered based on the system-level simulation and compared to measurements. The study involves the impairments characterization and their behavior in a transceiver system. The impairment decomposition method is performed in order to validate the measurements of error vector magnitude for QPSK transmission with variable baud-rates up to 4 GBd. We show that for a given RF bandwidth of 5 GHz, within an E-band RF chain configuration for downlink diplexer filters, the EVM performance related to deterministic linear impairments degrades by 3.3% (2.3 dB), while in case of uplink diplexer filters, it degrades by 4.25% (4.5 dB).

The paper reviews our recent experimental work in the area of multi-Gigabit fixed wireless links operating in the high millimeterwave frequency range. An E-band link is employed to transmit up to 6 Gbit/s over a line-of-sight terrestrial distance of 36.7 km using QPSK modulation, and 15 Gbit/s over 15 km using 8QAM. At 240 GHz, up to 64 Gbit/s QPSK are transmitted over a distance of 850 m. The paper details the unified architecture of the analog transmit-receive frontends, reports EVM and BER data for these links and discusses link budget calculations.

In this paper an E-band transmitter chain with a maximum RF output power of 29 dBm for a 1 GBd QPSK signal is presented. The high output power is achieved by applying AlGaN/GaN-based power amplifiers as final stage of a module chain which further comprises a GaAs mHEMT-based quadrature up-converter, LO frequency multiplier-by-eight and driver amplifiers. The output power remains higher than 27 dBm for up to 6 GBd symbol rate and a modulation complexity of up to 32 QAM. In this work the effect of different PSK and QAM modulation format as well as the baud rate on the transmitted RF power level is studied through measurements. The linearity of the dual GaN PA module is evaluated for different types of modulation formats.

This paper presents the wireless data transmission of complex modulated signals in the E-band using a MMIC-based link compared to the current state of the art in millimeter-wave wireless communication. Highly linear and extremely broadband frontend components in combination with the latest equipment to generate and analyze broadband complex data signals are used in this experiment. The received signal quality is evaluated in terms of EVM and BER. An error free QPSK transmission with a data rate of 40 Gbit/s over a wireless distance of 6m is presented, while the transmission of 80 Gbit/s signals, achieved by 16-QAM modulation, results in a BER of 3.7 × 10−3.

The influence of hydrometeors on a MMIC-based wireless data transmission at 240GHz carrier frequency was experimentally evaluated in a climatic wind tunnel over a distance of 90 m. Successful transmissions of up to 24 Gbit/s QPSK modulated signals through heavy rain at 43 mm/h and dense fog at 3 g/m 3 is achieved. The climatic impact is evaluated in terms of EVM. Reducing the bandwidth makes a transmission still possible with a BER

We present a PLL stabilized VCO at X-Band frequencies extended by a frequency multiplier-by-eight module forming a variable LO source for E-Band communication systems with enough output power to drive an E-Band mixer without additional post amplification. The module shows a 3-dB output bandwidth from 73 to 85 GHz with a saturated output power of 10 dBm. Together with the VCO module the source features a phase noise of −89 dBc/Hz at 100 kHz offset from the 76.8 GHz carrier.

In this paper, the transmission of broadband complex modulated signals with data rates up to 48 Gbit=s using an E-band MMIC-based analog frontend is shown. The paper presents the transmission of QPSK, 8-PSK and 16-QAM modulated signals with a symbol rate of 12 GBd. The received signal quality is evaluated in terms of error vector magnitude, which, measured in a coherent setup, shows values of −18.8 dB, −18.7 dB and −20.9 dB for the QPSK, 8-PSK and 16-QAM signal, respectively. Using a more application oriented incoherent setup, the signal quality decreases about 1 dB.

Based on active millimeter-wave monolithic integrated circuits (MMICs), a pair of receiver and transmitter modules have been developed and used for wireless data transmission experiments at 240 GHz with data rates of up to 40 Gbit/s. Both modules are driven with a subharmonic local oscillator, located at 120 GHz and feature broadband quadrature I/Q IF terminals. The receiver module has a maximum conversion gain of 3.8 dB at 240 GHz. The I/Q imbalance stays below 1.9 dB in the frequency range from 200 to 280 GHz. The transmitter achieves a maximum output power of -3.6 dBm.

The transmission of complex modulated data signals with data rates up to 30 Gbit/s is successfully realized using a 240 GHz wireless link based on active MMIC components. The paper presents the transmission of QPSK and 8-PSK modulated signals over a distance of 40 m as well as a characterization of the RF frontend based on S-parameter measurements and back-to-back signal transmission. The link quality is evaluated in terms of error vector magnitude (EVM) measurement. For a symbol rate of 10 GBd, the EVM measurement shows values of 10.3% and 15.2% for the QPSK and 8-PSK signal, respectively.