Airspy HF Plus High Peformance SDR Receiver
Airspy HF Plus High Peformance SDR Receiver The Software Defined Radio revolution brought great flexibility in VHF and UHF reception. Today Airspy offer the best wide band receivers which address these needs. Airspy also provide a high performance extension for weak-signal wide band reception on HF – something other competing solutions fail to address efficiently.Airspy HF+ is a paradigm shift in high performance HF radio design. It is a joint effort between Airspy, Itead Studio and a top-tier semiconductor company to build a state of the art SDR for HF and VHF bands.Like most high-end HF receivers, the HF+ uses very high dynamic range ADC’s and front-ends. But unlike the current offerings in the market, it also brings more frequency agility by using high performance passive mixers with an excellent polyphase harmonic rejection structure. No external band filtering is required unlike the lower end HF receivers, which makes it the ideal companion for light portable high performance operation.Both the architecture and level of integration achieved in this design allow Airspy to offer top performance reception at a very affordable price.
Unrivalled Noise Reduction Processing
Airspy and Itead Studios have spent a lot of time understanding RF noise, its structure, and how it interacts with legitimate signals. Today, they have one of the most flexible and acoustically pleasant noise reduction algorithms of the market. The applications range from high-fidelity hiss removal for Broadcast FM signals, to unburying weak SSB signals from the noise floor. Our algorithm doesn’t kill the highs to give you a false impression of loudness, yet it doesn’t have the typical high tone artifacts that plague popular noise reduction algorithms like LMS and Spectral Subtraction.
Airspy HF+ achieves excellent HF performance by means of a low-loss band filter, high linearity LNA, high linearity tunable RF filter, a polyphase harmonic rejection (HR) mixer that rejects up to the 21st harmonic and multi-stage analog and digital IF filtering.The 6 dB-stepped AGC gain is fully controlled by the software running in the DSP which optimizes the gain distribution in real time for optimal sensitivity and linearity. Harmonic rejection is a key issue in wide band HF receivers because of the large input signal bandwidth of the input signal. The output of the IF-filter is then digitalized by a high dynamic range sigma delta IF ADC for further signal processing in the digital domain.
Excellent VHF performance is also achieved by using optimized signal paths composed of band filters, high linearity LNAs with a stepped AGC, a polyphase harmonic rejection mixer and IF filters optimized for their respective bands.The amplifier gain is switchable in 3 dB-steps and fully controlled by the AGC running in the DSP. The RF signal is converted to baseband by a high linearity passive mixer with a polyphase harmonic rejection structure. The low-IF signal is then converted into the digital domain by the same IF ADC used in the HF chain.
The IF analog to digital converter (ADC) is a 4th order multi-bit noise shaping topology; it features very high dynamic range and linearity. The IF-ADC sampling rate is determined by a control algorithm running in the embedded DSP. This advanced technique adjusts the sampling rate depending on the tuning frequency with the goal of avoiding the disturbances and spurs generated by the switching discrete-time sections of the IF-ADC.
Digital Down Converter
Once the IF signal is digitalized, the high sample rate I/Q stream is then frequency translated and processed with cascaded CIC and FIR decimation stages. After every stage, the sample rate is reduced and the resolution increased. The final signal at the output has 18bit resolution and an alias rejection performance of 108 dBc. The data is then scaled to 16bit and sent to the Micro-Controller for streaming over USB.
The main advantages over techniques from the legacy super-heterodynes up to the now mainstream direct sampling is that the whole receiver chain is well protected against out of band blockers while still relaxing the RF filtering constraints, making it simple and cost effective.The natural filtering of the sigma-delta ADC combined with the excellent linearity and sensitivity of the analog chain reaches an unprecedented level of performance and integration.
Use it over the network!
Connect as many SDR applications as needed to the HF+, over the Internet or in your own local network with near zero latency thanks to the new SPY Server software.This setup basically brings all the flexibility of Web based SDRs while still benefiting from the full power of desktop applications. The IQ data is processed in the server with state of the art DSP and only the required chunk of spectrum is sent over the network. What is sent is the actual IQ signal, not compressed audio. This means you can use all your favorite plugins to process the IF, eliminate noise and perform heavy lifting of the signals as you are used to do with locally connected SDR’s.We have a tradition of building multi-tools, so we made sure the SPY Server runs on 32/64bit Windows and Linux on Intel and ARM processors without any compromises. Low cost Raspberry Pi 3 and Odroid boards are in the party.
HF coverage between 9 kHz .. 31 MHzVHF coverage between 60 .. 260 MHz-140.0 dBm (0.02 µV / 50 ohms at 15MHz) MDS Typ. at 500Hz bandwidth in HF-141.5 dBm MDS Typ. at 500 Hz bandwidth in FM Broadcast Band (60 – 108 MHz)-142.5 dBm MDS Typ. at 500 Hz bandwidth in VHF Aviation Band (118 – 136 MHz)-140.5 dBm MDS Typ. at 500 Hz bandwidth in VHF Commercial Band (136 – 174 MHz)-140.0 dBm MDS Typ. at 500 Hz bandwidth in the upper VHF Band (> 174 MHz)+15 dBm IIP3 on HF at maximum gain+13 dBm IIP3 on VHF at maximum gain110 dB blocking dynamic range (BDR) in HF95 dB blocking dynamic range (BDR) in VHF150+ dB combined selectivity (hardware + software)120 dB Image Rejection (software)Up to 660 kHz alias and image free output for 768 ksps IQ18 bit Embedded Digital Down Converter (DDC)22 bit! Resolution at 3 kHz channel using State of the Art DDC (SDR# and SDR-Console)+10 dBm Maximum RF input0.5 ppm high precision, low phase noise clock1 PPB! frequency adjustment capabilityVery low phase noise PLL (-110 dBc/Hz @ 1kHz separation @ 100 MHz)Best Noise reduction of the market using state of the art algorithms2 x High Dynamic Range Sigma Delta ADCs @ up to 36 MSPSNo Silicon RF switch to introduce IMD in the HF pathRoutable RF inputs with simple modificationWide Band RF filter bankTracking RF filtersSharp IF filters with 0.1 dB rippleSmart AGC with real time optimization of the gain distributionAll RF inputs are matched to 50 ohms4 x Programmable GPIO’sNo drivers required! 100% Plug-and-play on Windows Vista, Seven, 8, 8.1 and 10Industrial Operating Temperature: -45°C to 85°CTypical Applications
High Performance Networked HF/VHF RadioHam Radio (HF + 2m)Short Wave Listening (SWL)AM DXFM DXVHF-L TV DXRemote Telemetry Radio ReceiverLow Bands IoTSupported Software
The gold standard SDR#The other excellent SDR suite, SDR-ConsoleThe suiss-army SDR knife for Linux and Mac, GQRXAll ExtIO based software (HDSDR, Studio1, etc.)Check the full list of tools in our download pageSupported Operating Systems
Windows Vista, 7, 8, 8.1 and 10Linux*BSDOSXSupported Hardware
Intel compatible PCRaspberry Pi 2 and 3Odroid C1, C2 and XU4Many other Single Board Computers (SBC)Minimum hardware requirements
1GHz Pentium or ARM1GB of RAM (to run your own OS, HF+ barely needs 1MB of memory)High speed USB 2.0 controllerFully Open-Source driver
Open source, multi-platform user mode driver libairspyhf on github