The Best Open Source RF Signal Generator Just Got Better

ERASynth Micro is an open source signal generator with impressive features. Everyone can afford it, including makers, hackers, students, ham radio and SDR users. ERASynth Micro can be powered from a USB port and features an LCD interface for standalone use without a computer or phone. It can generate low phase noise RF signals from 12.5 MHz to 6.4 GHz with a dual PLL architecture.

Features & Specifications

• Architecture: Dual loop Fractional-N PLL
• Frequency Range: 12.5 MHz to 6.4 GHz
• Amplitude Range: -50 to +15 dBm
• Phase Noise: -115 dBc/Hz @ 1 GHz output and 10 kHz offset
• Frequency Switching Time: 1 ms (typical)
• Reference: Ultra-low noise 50 MHz VCXO locked to a ±500 ppb TCXO
• MCU: ATMEGA32U4 (same as in the Arduino Micro)
• Interfaces:
  • Touch Display Module (3.2” Nextion NX4024T032)
  • Micro-USB for power input and serial access
  • REF In (SMA) for external reference input
  • REF Out (SMA) for 10 MHz reference output
  • RF Out (SMA)
  • Expansion connector: External trigger input, external modulation input, microphone input, GPIO (I2C), and SPI
• Modulation: AM, FM, Pulse (Internal and external)
• Size: 57 mm x 118 mm x 23 mm
• Weight: <120 g (including the LCD screen)
• Power Input: 5 V
• Power Consumption: <2 W
• Enclosure: Injection molded plastic case
• Open Source: Schematics, embedded Arduino code, LCD screen source code, and RS-232 command set

Quicklinks

• Great Features, Micro MCU
• Phase Noise
• Enclosure
• Plug & Play Design
• External Reference I/O
• Modulation
• Onboard EEPROM
• Vibration Motor
• Expansion Connector

Makers/Hackers:

RF signal generators are expensive pieces of test equipment mainly used by pro engineers. ERASynth Micro aims remove the cost barrier and make quality RF signal synthesis accessible to everyone, especially the makers.

Students:

ERASynth Micro is for everyone who wants to learn how signal generators work. Since it is open-source and open-schematics, students or anyone who is curious about the inner details of signal synthesis can benefit from ERASynth Micro. You can learn a lot more by reverse engineering and hacking than you can learn in an entire year of a $50k/year engineering school. Learning about the design of test equipment turned Jim Williams into one of the best analog engineers in the world. ERASynth Micro’s advanced design will certainly teach you several RF tricks.

Professionals:

Professional engineers will find ERASynth Micro to be a very good alternative to many of their existing signal generators.

Anyone else:

ERASynth Micro is for anyone interested in RF testing. Below is a short list of application areas where users can take advantage of ERASynth Micro:

• General purpose RF testing. For example, to measure the gain of an amplifier, ERASynth Micro can be used as the stimulus source.
• Test signal source for SDR. People who are using any of many SDR platforms can use ERASynth Micro as the test signal source for testing and calibration of their SDR devices.
• An agile LO source for up and down-convertors.
• Clock source for ADCs and DACs.

ERASynth Micro Simplified Block Diagram

Great Features, Micro MCU

ERASynth Micro takes its name from Arduino Micro board. Its design features an ATmega32U4 MCU (same as Arduino Micro) and can be programmed easily using Arduino. ERASynth Micro’s embedded code was developed very efficiently and packs lots of features. ERASynth Micro also features an external EEPROM to store static data such as amplitude calibration and local settings.

Phase Noise

ERASynth Micro Phase Noise @ 1 GHz Output, 1 kHz offset

ERASynth Micro Phase Noise @ 1 GHz Output, 10 kHz offset

ERASynth Micro Phase Noise @ 1 GHz Output, 100 kHz offset

ERASynth Micro Phase Noise @ 1 GHz Output, 1 MHz offset

Enclosure

We developed ERASynth Micro to keep cost to a minimum. That is why our first choice for the enclosure was an acrylic case. After couple of trials with acrylic cases, we decided to use a full-blown injection-molded plastic enclosure. We found a local manufacturer and started the design procedure. After couple of revisions, final enclosure was ready.

Touch Display Module

By incorporating a 3.2” touch display module (Nextion NX4024T032) ERASynth Micro requires no additional host computer for control mechanism. The menus on the LCD GUI mimic professional test equipment menu structure, and so are very intuitive and easy to use.

Plug & Play

ERASynth Micro consumes very low power. It can be powered from the ubiquitous USB port. Once powered, it takes a few seconds to boot up and, thanks to its LCD screen, it is ready for action within seconds.

External Reference Input/Output

Although ERASynth Micro is small enough to fit into your pocket, it still doesn’t sacrifice features such as reference input/output. Due to space constraints, ERASynth Micro provides a single connector for reference in and out. When internal reference is selected, the internal 10 MHz TCXO signal is output from the REF connector. Likewise, when external reference is selected, an external 10 MHz reference signal can be applied to REF connector for synchronous operation.

Modulation

ERASynth Micro can perform AM, FM and Pulse modulations. The modulating (baseband) signal can be created internally or can be fed from external modulation input. Internal modulating signal can be selected as sine, triangle, ramp or square-wave. For external modulation, a signal can be applied to the MOD input via the expansion connector. Just like its predecessor ERASynth, ERASynth Micro also features a microphone input that can be used for many applications.

Onboard EEPROM

ERASynth has 64KB EEPROM. We allocated half of the space for amplitude calibration data. The rest of the EEPROM is used to store local settings and parameters. Inclusion of the EEPROM enables ERASynth Micro remember its configuration (frequency, amplitude level, REF in/out etc. settings). Upon power-up, the saved configuration is retrieved and applied automatically.

Vibration Motor

We added a vibration motor to enhance the feeling of device. When a button on the LCD GUI is clicked, motor vibrates like a cell phone. This provides a haptic confirmation for data entry.

Expansion Connector

ERASynth Micro was developed to be Arduino compatible. Everything needed to create an Arduino hub is routed to the expansion connector. SPI pins, Reset pin of ATmega32U4, Trigger pin, and several other GPIO pins are provided at the expansion connector. Users can easily modify the firmware to implement additional features.

Conector Pinout

ERASynth Micro Comparison Table

Package Content

ERASynth Micro is going to be delivered with a Micro-USB cable and a stylus pen.

Manufacturing Plan

We have already manufactured the first 100 units. If we receive pledges for more than 100 units, we will manufacture the extra units. Manufacturing extra units is not a big challenge for us since we already have all of the major BoM items (ICs, PCBs, LCD screen etc.) in stock.

Shipping & Fulfillment

ERASynth Micros will be shipping from Crowd Supply’s warehouse in the USA. We can’t pre-pay VAT, so if you are living in a country that collects VAT upon import, you will likely have to pay that and deal with customs clearance. International shipments will be fulfilled with Priority Mail, which is why the shipping fee is $25 USD for all international shipments. This fee does not include any applicable taxes, duties, etc. For more information about ordering, paying, and shipping please visit this Crowd Supply Guide page.

Risks & Challenges

At this time we do not foresee many risks or challenges with producing this product. During past several months, we went through several PCB and enclosure iterations and refined the product and have already produced 100 units that are ready to ship.

Support & Documentation

ERASynth Micro schematics, Arduino firmware, LCD GUI source codes, datasheet, and user guide are all available on ERA Instruments’ GitHub repository.

• ERASynth Micro Datasheet

If you have a question about ordering, paying, or shipping, please refer to The Crowd Supply Guide.

If you have a technical question about the operation of the ERASynth Micro or any of its applications, please ask the creators your question directly.