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vor 6 Jahren

6-2017

  • Text
  • Komponenten
  • Technik
  • Radio
  • Filter
  • Oszillatoren
  • Quarze
  • Emv
  • Wireless
  • Messtechnik
  • Bauelemente
Fachzeitschrift für Hochfrequenz- und Mikrowellentechnik

RF & Wireless Fig. 3:

RF & Wireless Fig. 3: Third-party EM Simulators can be selected as the EM simulator Design optimization has been improved with the introduction of genetic algorithm methods (advanced genetic and particle swarm), leveraged from the evolutionary algorithms employed within AntSyn antenna design and synthesis software (awrcorp. com/antsyn). These optimizers use recombination and selection to rapidly and robustly explore a large number of points randomly distributed over the design space. This results in a more efficient and faster approach to investigating design possibilities and identifying optimum solutions. Filter Synthesis iFilter, an integrated filter synthesis module (Fig. 1), seamlessly runs as a wizard within NI AWR Design Environment, enabling designers to keep filter designs and their evolution a part of the entire, managed circuit design project. iFilter’s 5G/LTE-A Communications 5G candidate waveform modulators are available as a 5G waveforms library in V13. Along with the support for carrier aggregation of contiguous and non-contiguous spectrum, V13 allows higher data capacity through wideband (40 MHz) aggregation. The added 5G functionality includes signal generation and demodulation to allow for full system simulation and measurements such as BER, ACPR, and EVM. V13 Highlights • New 5G waveforms library (OFDM variations, GFDM, FBMC) • Channel models: METIS 2020 • New multi-beam examples • Addresses physical-layer (PHY) level design for 5G mmWave bands • MIMO and multiple-in-multiple-out (MIMO) PHY link level simulations • Transceiver design and analysis • Tradeoffs in RF link architecture and component selection • Carrier aggregation for DL/UL • BER/block-error rate (BLER) measurements intuitive user interface quickly has users designing filters, connecting them directly to circuitry, and making tradeoffs that positively impact their design. iFilter offers both automatic and manual flows. The automatic flow enables extraction of transmission zeros (TZ) such as DC, INF, and finite, as well as application of transformations from 80+ models. In the manual flow, the user manually places and distributes the transmission zeros. For a standard bandpass filter implementation, zeros can be weighted on the low side or the high side of the passband, allowing for extra emphasis on filter rejection for the selected side. In addition, transmission zeros can be added manually at any desired frequency. The user extracts transmission zeros in a preferred order and applies specific transformations to yield a better design. The completed filter can be implemented in Microwave Office circuit design software with a single click for further refinement and optimization. Measurement Graphs Even before a simulation is complete, the new marching waveforms feature in V13 begins plotting “real-time” measurement data on defined measurement graphs, giving designers an early preview of simulation results and the opportunity to adjust a design or simulation parameter if there are any issues with the design response or simulation setup. To help users assess measurement data, two new marker types, auto-search markers and offset markers, are now available. Auto-search markers automatically search for a userspecified feature such as trace maximum and shift along the x-axis to stay aligned with the feature as the trace is updated due to tuning, optimization or other performance goals. Offset markers maintain a specified x or y offset from another marker on the trace. In addition, richtext notes can now be attached to markers to help document graphs and share insights with fellow designers. Circuit and System Simulation and Libraries APLAC, the high-frequency circuit simulation technology seamlessly integrated into NI AWR Design Environment Microwave Office and Analog Office, has been developed to minimize memory requirements 60 hf-praxis 6/2017

RF & Wireless Fig. 4: Visual System Simulator can fully analyze complete phased array systems and simulation run times while maintaining accuracy. To address nonlinear devices for communication systems, APLAC now includes circuit envelope, capable of addressing circuits excited by non-periodic signal sources such as modulated RF signals. The associated measurements provide the timevarying voltage or current of a particular carrier and the associated spectrum surrounding that carrier. With the added capability of simulating modulated waveforms with circuit envelope, new sources have been added to describe modulated waveforms, such as the ability to specify the IQ data of a modulated signal. The speed and robustness of the APLAC transient (time-domain) simulation engine is enhanced with a new core algorithm and improved time-step algorithm. Other developments include new error control and a transient preset option that can be set to Accurate, Moderate, or Fast. The transient-assisted HB (TAHB) option, used for digital divider circuits and accurate nonlinear phase-noise measurements of analog and RF applications, can be leveraged in V13 for oscillator analysis by setting the TAHB options to Disabled, Convergence Aid, or Initial Guess. With time-domain simulations such as transient and circuit envelope, it is necessary to extract a time-domain model for passive devices, S-parameters, and transmission lines. Improvements to the time-domain model in V13 include a better speedto-accuracy ratio in the extraction of S-parameter data, more robust handling of poor quality data, and more robust passivity enforcement. For power amplifier (PA) designers, this latest version of Visual System Simulator (VSS) software supports system-level load pull to generate contours for communication performance metrics such as adjacent channel power ratio (ACPR) and error vector magnitude (EVM). For amplifier designs, Microwave Office V13 now supports nested source/load pull contours, enabling designers to directly observe changing source and load contours as a function of source and load impedance terminations. This unique capability allows designers to provide a new terminating impedance to either the source or load and directly observe the change to the contours at the other port without having to re-simulate the circuit, thereby eliminating the timeconsuming iterative approach to source/load matching. System design for communication applications is further enabled with new capabilities introduced in V13 of VSS. The software now provides LTE- Advanced (LTE-A) support for carrier aggregation of intraband and interband component carriers and 5G candidate modulated waveforms such as filter-bank multicarrier (FBMC) (Fig. 2), generalized frequency-division multiplexing (GFDM), and filtered orthogonal frequency-division multiplexing (F-OFDM). These technologies take advantage of faster processing speeds to offer higher data rates and are therefore being considered to replace OFDM download (DL) and single-carrier frequencydivision multiple access (SC- FDMA) upload (UL). For sharing and re-using results in subsequent simulations, a new outpthe type of ut file measurement feature in VSS writes a compatible nonlinear behavioral model text file that includes information on fundamental input, fundamental output, intermodulation (IM3) products (for two-tone simulations), harmonics (for one-tone simulations), S11, S22, characteristic input and output impedances, and noise figure (NF). In addition, signal heritage information obtained from the RF Inspector (RFI) technology within VSS can be exported to an .xml file. hf-praxis 6/2017 61

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