ERASynth is a high quality portable signal generator at a price point affordable by everyone including makers, students, universities, research labs, and start-ups.
RF signal generators are expensive pieces of test equipment typically only accessible by pro engineers. ERASynth removes the cost barriers and makes quality RF signal synthesis accessible to everyone, especially budget-conscious makers.
ERASynth is for everyone who wants to learn how signal generators work. Since it is open source with open schematics, students or anyone who is curious about the inner details of signal synthesis can learn from ERASynth. You can learn a lot by reverse engineering and hacking, without having to pay $50k in tuition in engineering program. After all, learning the design of test equipment turned Jim Williams into one of the best analog engineers in the world. ERASynth’s advanced design will certainly teach you several RF tricks.
Professional engineers will find ERASynth is a very good alternative to many of their existing signal generators. If you are professional engineer, you can compare it yourself: find the lowest cost equipment on your bench that can give you a 1 GHz signal with -120 dBc/Hz or better phase noise at 10 kHz offset. Its price tag will be several times more than ERASynth’s. See the comparison charts below to learn more about how ERASynth compares to common signal generators.
With all the cuts in research funds, who can afford to spend tens of thousands on signal generators? Whether you are a college professor studying Gigasample converters or a start-up developing state-of-the-art converter technology, you need to clock ADC/DAC somehow. Check out the specs, you will find ERASynth may very well be your next clock source. Besides the price, ERASynth’s portability will definitely help when you are out in the field.
ERASynth is for anyone interested in RF testing. Below is a short list of application areas where users can take advantage of ERASynth:
|1. Mini-USB for Serial Access||12. RF Attenuators (RFSA2113)|
|2. Wi-Fi Module (ESP8266)||13. RF Output (50 Ω)|
|3. Wi-Fi Antenna Connector||14. Wideband PLL with VCO (LMX2594 or LMX2595)|
|4. Micro-USB Input for Power||15. 10 MHz Reference Output|
|5. Microphone Input||16. 10 MHz Reference Input|
|6. Trigger and External Modulation Input||17. ±0.5ppm TCXO (10 MHz)|
|7. Step-down Switcher||18. ±25ppb OCXO (AOCJYR)|
|8. Step-up Switcher||19. Ultralow Phase Noise VCXO (ABLNO-V)|
|9. RF LDOs (TPS7A8300)||20. Tunable Reference Generator (LMX2594)|
|10. DDS (AD9913)||21. Arduino Due MCU (ATSAM3X8EA-CU)|
|11. RF Attenuators (RFSA2023)||22. Serial to USB Bridge (ATmega16U2)|
Low cost, USB-controlled RF signal generators are available from a multitude of vendors. These signal generators usually include a single fractional PLL IC with integrated VCO. Examples of such PLL ICs are: ADF435x and ADF5355 series from ADI, LMX series from TI, MAX2870 from Maxim, and STuW series from STMicro. These signal generators are mostly a close replica of the eval board of the PLL/VCO IC and they are usually limited in terms of performance. ERASynth architecture provides several built-in features that overcome these limitations.
While fractional-N PLLs are great for generating frequencies with fine frequency resolution, they suffer from a phenomenon called "integer boundary spurs" (IB spurs). IB spurs are visible at the output of a frac-N PLL IC when the output frequency is close to an integer multiple of the reference frequency. For example, generating an RF output of 6000.01 GHz from a 100 MHz reference will result in IB spurs as large as -30 dBc. This level of performance may be acceptable for some specific application, but generally it is unacceptable for signal generators. ERASynth’s multi-loop architecture eliminates IB spurs by varying the reference in fine steps while keeping the main loop in integer-N mode. This architecture not only diminishes IB spurs but also helps reduce phase noise. PLL IC’s phase noise floors are usually lower by 2-3 dB in integer-N mode compared to frac-N mode.
ERASynth rev2 (turquoise) vs ADF5355 Eval Board (yellow) @ 6.14401418 GHz. ERASynth rev2 uses ADF4356 as the main PLL.
On top of the dual loop PLL that generates the RF output, ERASynth adds another PLL to minimize the reference phase noise. While many competitors use low-cost TCXOs in the range of a few tens of MHz, ERASynth uses a 100 MHz VCXO with a very low phase noise floor. This VCXO is stabilized with a ±0.5 ppm TCXO or ±25ppb OCXO depending on the model. The VCXO may also be locked to an external 10 MHz reference.
|-||ERA Instruments ERASynth||ERA Instruments ERASynth+||Vaunix LMS-602D||DS Instruments SG6000LD||Windfreak SynthHD|
|Architecture||Int-N Driven by Frac-N||Int-N Driven by Frac-N||?*||Frac-N||Frac-N|
|Frequency Range||250 kHz to 6 GHz||250 kHz to 15 GHz||1.5 to 6 GHz||25 to 6000 MHz and 6 to 12 GHz||54 MHz to 13.6 GHz|
|Frequency Resolution||1 Hz||1 Hz||100 Hz||~3 kHz||0.1Hz|
|Max Frequency Error||0 Hz||0 Hz||?*||~3 kHz||0 Hz|
|Amplitude Range||-60 to +15 dBm||-60 to +15 dBm||-40 to +10 dBm||typical +11 dBm with 31.5dB attenuator||?|
|Phase Noise at 1 GHz and 10 kHz offset||-120 dBc/Hz||-120 dBc/Hz||-97 dBc/Hz||-91 dBc/Hz (*)||-100 dBc/Hz|
|Frequency Switching Time||250 µs||250 µs||100 µs||?*||4 ms|
|Subharmonics||None||None||None||over 6 to 12 GHz||over 6.8 to 13.6 GHz|
|Reference||100 MHz VCXO locked to a ±0.5 ppm TCXO||100 MHz VCXO locked to a ±25 ppb OCXO & ±0.5 ppm TCXO||±2 ppm||±2.5 ppm 10 MHz TCXO||±2.5 ppm 10/27 MHz TCXO|
|REF IN/REF OUT Connectors||Yes||Yes||Only REF IN. REF OUT is optional||Only REF IN||Only REF IN|
|Trigger Input||Yes||Yes||optional ($400 USD)||No||Yes|
|Enclosure||Milled aluminum||Milled aluminum||Milled aluminum||Extruded aluminum||Extruded aluminum|
|Power Input||5 to 12 V||5 to 12 V||5 V||5 V||6 V|
|Power Input Connector||micro USB||micro USB||mini USB||micro USB||power jack|
|Open Source||Schematics, firmware and GUI||Schematics, firmware and GUI||Nothing||Nothing||LabVIEW GUI|
|GUI platform||Platform independent web-based GUI||Platform independent web-based GUI||Windows||Windows||Windows and Linux|
|-||ERA Instruments ERASynth||ERA Instruments ERASynth+||Rigol DSG830||Stanford Resarch SG386||Keysight N5171B EXA|
|Architecture||Int-N Driven by Frac-N||Int-N Driven by Frac-N||Int-N Driven by DDS?||Rational Approximation Frequency Synthesis||Proprietry Frac-N ASIC|
|Frequency Range||250 kHz to 6 GHz||250 kHz to 15 GHz||9 kHz to 3 GHz||DC to 6 GHz||9 kHz to 6 GHz|
|Frequency Resolution||1 Hz||1 Hz||0.01 Hz||1 µHz||0.001 Hz|
|Amplitude Range||-60 to +15 dBm||-60 to +15 dBm||-110 to +13 dBm||-110 to +16.5 dBm||-140 to +18 dBm|
|Level Control||Open Loop||Open Loop||Closed Loop ALC||Closed Loop ALC||Closed Loop ALC|
|Calibration over Temperature||Only at Room Temp||Only at Room Temp||0 to 50°C||0 to 45°C||0 to 50°C|
|Phase Noise at 1 GHz, 10 kHz offset||-120 dBc/Hz||-120 dBc/Hz||-104 dBc/Hz||-114 dBc/Hz||-122 dBc/Hz|
|Frequency Switching Time||250 µs||250 µs||<10000 µs||8000 µs||<5000 µs standard, <800 µs optional|
|Harmonics||-10 dBc typical||-10 dBc typical||<-30 dBc||<-35 dBc||<-35 dBc|
|Reference||100 MHz VCXO locked to a ±0.5 ppm TCXO||100 MHz VCXO locked to a ±25 ppb OCXO||±2 ppm TCXO or optional ±5 ppb OCXO||±2 ppb OCXO||±1 ppm TCXO or optional ±5 ppb OCXO|
|Modulation||AM, FM and pulse||AM, FM and pulse||AM/FM/ΦM and optional pulse||AM/FM/ΦM/pulse||optional AM/FM/ΦM/pulse|
ERASynth schematics, Arduino firmware, web and Windows GUI source codes, datasheet and user guide are all available on ERA Instruments GitHub repository.