Tag Archives: RF

ERASynth, An Arduino-Compatible RF Signal Generator

A young startup based in Istanbul has launched a crowdfunding campaign to bring its RF Signal Generator “ERASynth” into mass production. ERA Instruments is specializing in creating solutions in the areas of analysis, modelling, design and development of Communcation, RADAR and SIGINT systems.

ERASynth is a portable analog signal generator that generates RF frequencies from 250 kHz to 15 GHz. The output signal is produced using an advanced multiloop PLL architecture to minimize the phase noise and spurious. This clean signal can be used as a stimulus source for RF testing, an LO source for down-conversion or up-conversion, a clock source for data converters, and as a test signal source for software defined radio (SDR).

ERASynth Features & Specifications

  • Architecture: Multiloop Integer-N PLL driven by a tunable reference. No fractional-N or integer boundary spurs
  • Frequency Range:
    • ERASynth: 10 MHz to 6 GHz
    • ERASynth+: 250 kHz to 15 GHz
  • Amplitude Range: -60 to +15 dBm
  • Phase Noise: typical phase noise @ 1 GHz output and 10 kHz offset. -120 dBc/Hz for the standard version and -125 dBc/Hz the plus version.
  • Frequency Switching Time: 100 µs
  • Reference: Ultra-low noise 100 MHz VCXO locked to a ±0.5 ppm TCXO for standard version and ±25 ppb OCXO for the plus one.
  • MCU: Arduino Due board with BGA package Atmel Microcontroller (ATSAM3X8EA-CU)
  • Interfaces:
    • Wi-Fi interface for web-based GUI access
    • Serial-USB (mini USB) for serial access
    • Micro USB for power input
    • Trigger Input (SMA) for triggered sweep
    • REF In (SMA) for external reference input
    • REF Out (SMA) for 10 MHz reference output
    • RF Out
  • Dimensions: 10 cm x 14.5 cm x 2 cm
  • Weight: < 350 g (12.5 oz)
  • Power Input: 5 to 12 V
  • Power Consumption:
    • < 6 W for ERASynth
    • < 7 W for ERASynth+
  • Enclosure: Precision-milled, nickel-plated aluminum case
  • Open Source: Schematics, embedded Arduino code, Web GUI source code, and RS-232 command set

ERASynth is only 10 x 14.5 x 2 cm sized and it is consuming less than 7 Watts. It can be powered by a cell phone power-bank. Inclusion of an on-board Wi-Fi module and an open source web GUI makes ERASynth ideal for portable applications. Also its price make it affordable by everyone including makers, students, universities, research labs, and startups.

Compared with other low cost USB signal generators, ERASynth provides better features in many factors. It also delivers similar functionality of the professional RF signal generator with lower price. The tables below demonstrate the comparison.

The crowdfunding campaign on Crowd Supply will be closed by tomorrow, they raised about $35,000 of $25,000 goal. You can order your ERASynth for $500 and ERASynth+ for $750. More technical details are available on the campaign page.

PandwaRF, A Portable Radio Analysis Tool

PandwaRF, is a portable low-power RF device that captures, analyses and re-transmits RF signals via an Android device or a Linux PC. It uses Bluetooth (BLE) or USB connection to transmit data in a simple and fast way, comes in the form of a controllable housing from a smartphone or a computer.

This pocket-size device operates at sub-1 GHz range, and it replaced the ‘standard SDR Grind’ of capturing, demodulating, analyzing, modifying and replaying by hand with a simple powerful interface.

The PandwaRF consists of a capable hardware device, tailored for beginners and advanced users, with an application that runs either on an Android device or on a PC. The Android interface provides full functionality to control and customize the PandwaRF easily using JavaScript.

Technical details of the PandwaRF:

  • Bluetooth Smart Module ISP130301, based on nRF51
  • CC1111 Low-Power SoC with Sub-1 GHz RF Transceiver
  • Multi frequencies (from 300 MHz to 928 MHz)
  • Multi modulation (ASK/OOK/MSK/2-FSK/GFSK)
  • Transmit and receive in half duplex mode
  • Support data rates up to 500 kBaud
  • Open hardware
  • Full speed USB: 12 Mbps (Linux or Android)
  • Bluetooth Smart 4.0 (Android/iOS)
  • USB charging & battery powered
  • 4 buttons to assign codes
  • 4 Status LEDs
  • 16 Mbit Flash Memory to save custom RF protocols
  • Rechargeable battery powered for stand-alone operation
  • Battery fuel gauge
  • RX amplifier for improved sensitivity: +13dB from 300MHz-1GHz
  • TX amplifier for higher output power: +20dB @ 433MHz & +17dB @ 900MHz
  • SMA connector for external antenna
  • Antenna port power control for external LNA
  • 22-pin expansion and programming header
  • Included: Battery and injection molded plastic enclosure

PandwaRF features are not fully complete yet, the developers had finished captured data processing offload, radio scripting (JavaScript & Python), RF packet sniffer, and spectrum analyzer. Other features are still in development process.

The device is available in three options, the Bare version is about $120 and comes without housing and without battery, the standard version is about $142 with battery and black case, in addition the extended version with enhanced features.

You can reach more information and order your PandwaRF on the official website.

6 Channel RF Remote Controller Using CC2500 RF Modules

The 6 Channel RF Remote Controller designed using CC2500 RF Transceiver modules and PIC16F1847 micro-controller from microchip. Transmitter provided with 6 tact switch, 4 Address Jumpers to pair multiple unit so they don’t interfere with each other. Board provided with power LED, valid transmission LED. Project works with 5 V DC, On board LM1117-3.3V regulator for CC2500 Module.  Two in one PCB can be used as Transmitter & Receiver.

Receiver works with 5V DC. 4 Jumper to paring RX& TX units, valid signal LED, power LED, and 9 Pin connector for outputs.  Same PCB is used as transmitter and receiver.  All outputs are Latch Type and TTL 5V Signal for easy interface with other devices like Relay Boards, Solid State Relays.

6 Channel RF Remote Controller Using CC2500 RF Modules – [Link]

Siglent SSA3032X Spectrum Analyzer Review & Experiments

Afroman reviews Siglent’s SSA3000X series spectrum analyzer and all the options. There is some RF information for beginners and usage experiments are also performed.

Siglent SSA3032X Spectrum Analyzer Review & Experiments [Link]

Send & Receive Radio With A Single Chip

Fitting transmit and receive capabilities of radio signals into one device may be impossible without using a significant filter, which is needed to isolate sent and received signals from each other.

The major obstacle to achieve that is the weakness of the received signal compared with the much stronger transmitted signal. However, researchers from Cornell University found their way to jump over this obstacle and created a two-way transceiver chip.

Alyosha Molnar, associate professor of electrical and computer engineering (ECE), and Alyssa Apsel, professor of ECE, had come up with a new solution to separate the signals. They made the transmitter consist of six sub-transmitters hooked into an artificial transmission line. Each one sends a weighted signal at regular intervals which combined with others such as a radio frequency signal in the forward direction, and at the same time they cancel each other in the opposite direction (towards to receiver).

The programmability of the individual outputs allows this simultaneous summation and cancellation to be tuned across a wide range of frequencies, and to adjust to signal strength at the antenna.

“You put the antenna at one end and the amplified signal goes out the antenna, and you put the receiver at the other end and that’s where the nulling happens,” Molnar said. “Your receiver sees the antenna through this wire, the transmission line, but it doesn’t see the transmit signal because it’s canceling itself out at that end.”

This research is based on a research reported six years ago by a group from Stanford University, which demonstrated a way for the transmitter to filter its own transmission, allowing the weaker incoming signal to be heard.

One of the sub-transmitter concept enhancements is that it will work over a range of frequencies, and instead of using a filter for every band, signal separation can be controlled digitally.

“You could have a single device that can be anything,” Apsel said. “You wouldn’t have to buy a new piece of equipment to have the newest version of it.”

You can find the full research at the IEEE Journal of Solid State Physics.

MDBT42Q, nRF52832-based BLE module

The open hardware innovation platform Seeedstudio produces the MDBT42Q, a Bluetooth Low Energy (BLE) module. It is a BT 4.0, BT 4.1 and BT 4.2 module designed based on Nordic nRF52832 SoC, a powerful, highly flexible ultra-low power multiprotocol SoC ideally suited for Bluetooth low energy, ANT and 2.4GHz ultra low-power wireless applications.

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MDBT42Q features a dual transmission mode of BLE and 2.4 GHz RF with over 80 meters working distance in open space. It is a 16 x 10 x 2.2 mm board which contains GPIO, SPI, UART, I2C, I2S, PWM and ADC interfaces for connecting peripherals and sensors.

nrf52832_mediumThe nRF52832 SoC is built around a 32-bit ARM® Cortex™-M4F CPU with 512kB and 64kB RAM. The embedded 2.4GHz transceiver supports Bluetooth low energy, ANT and proprietary 2.4 GHz protocol stack. It is on air compatible with the nRF51 Series, nRF24L and nRF24AP Series products from Nordic Semiconductor.

MDBT42Q Specifications:

  • Multi-protocol 2.4GHz radio
  • 32-bit ARM Cortex – M4F processor
  • 512KB flash programmed memory and 64KB RAM
  • Software stacks available as downloads
  • Application development independent from protocol stack
  • On-air compatible with nRF51, nRF24AP and nRF24L series
  • Programmable output power from +4dBm to -20dBm
  • RAM mapped FIFOs using EasyDMA
  • Dynamic on-air payload length up to 256 bytes
  • Flexible and configurable 32 pin GPIO
  • Simple ON / OFF global power mode
  • Full set of digital interface all with Easy DMA including:
  • 3 x Hardware SPI master ; 3 x Hardware SPI slave
  • 2 x two-wire master ; 2 x two-wire slave
  • 1 x UART (CTS / RTS)
  • PDM for digital microphone
  • I2S for audio
  • 12-bit / 200KSPS ADC
  • 128-bit AES ECB / CCM / AAR co-processor
  • Lowe cost external crystal 32MHz ± 40ppm for Bluetooth ; ± 50ppm for ANT Plus
  • Lowe power 32MHz crystal and RC oscillators
  • Wide supply voltage range 1.7V to 3.6V
  • On-chip DC/DC buck converter
  • Individual power management for all peripherals
  • Timer counter
  • 3 x 24-bit RTC
  • NFC-A tag interface for OOB pairing
  • RoHS and REACH compliant

pcb

This BLE module can be used in a wide range of applications, such as Internet of Things (IoT), Personal Area Networks, Interactive entertainment devices, Beacons, A4WP wireless chargers and devices, Remote control toys, and computer peripherals and I/O devices.

Full specifications, datasheet, and product documents are available at seeedstudio store, it can be backordered for only $10.

MAX11311 – The Powerful Configurable Mixed Signal I/O

The MAX11311 is industry’s first configurable high-voltage mixed-signal I/O that allows user-defined ADC, DAC, or GPIO functionality.

Programming MAX11311 is very easy. A nice GUI tool helps to generate the right register values. If you want to make a universal signal processing board with a good number of I/O, it often gets very difficult to select a correct microcontroller. Finally, when you select one, it either has less I/O than you need or has fair enough number of I/O but burns your pocket. But if you know about MAX11311, then you’ve got a perfect solution.

Description:

The MAX11311 integrates a PIXI™, a 12-bit analog-to-digital converter (ADC), and a 12-bit digital-to-analog converter (DAC) in a single integrated circuit. This device offers 12 high voltage, bipolar ports. Each of the ports is configurable as an ADC analog input, a DAC analog output, a general-purpose input output (GPIO), or an analog switch terminal. One internal and two external temperature sensors track junction and environmental temperature. This feature prevents thermal runaway. Adjacent pairs of ports are configurable as a logic-level translator for open-drain devices or an analog switch.

MAX11311 MIcrocontroller Block Diagram
MAX11311 Mixed Signal I/O Block Diagram

Features:

  • Up to 12 12-Bit ADC Inputs
    • Single-Ended, Differential, or Pseudo-Differential Range Options: 0 to 2.5V, ±5V, 0 to +10V, -10V to 0V
    • Programmable sample averaging per ADC port
    • Unique voltage reference for each ADC PIXI port
  • Up to 12 12-Bit DAC Outputs
    • Range options: ±5V, 0 to +10V, -10V to 0V
    • 25mA current drive capability with over-current protection
  • Up to 12 General-Purpose Digital I/Os (GPIO)
    • 0 to +5V GPI input range
    • 0 to +2.5V GPI programmable threshold range
    • 0 to +10V GPO programmable output range
    • Logic-Level Shifting Between any two pins
  • 60Ω analog switch between adjacent PIXI Ports
  • Internal/External temperature sensors with ±1°C Accuracy

Applications:

You can use this chip as an expansion module to MCUs in various applications. Let’s see the list:

  • Base station RF power device bias controllers
  • Control for optical components
  • Industrial control and automation
  • Power supply monitoring
  • System supervision and control
  • Universal signal processing

Conclusion:

The MAX11311 adapts perfectly to specific application requirements and allows for easy reconfiguration as the system needs further change. It also reduces BOM (Bill of Materials) cost with fewer external components in a small footprint.

To know more about this awesome chip, refer to the datasheet.

NUT4NT, Open-Source 4-Channel GNSS Receiver Development Board

Although the industry of professional satellite navigation systems is limited to experts and large companies, Amungo Navigation is working towards bringing this industry to individual developers, small companies, and startups through its new open source platform NUT4NT.

NT1065 chip
NT1065 chip

NUT4NT is a development board which implements NT1065 chip with USB 3.0 interface. NT1065 is a Global Navigation Satellite System (GNSS) receiver designed by NTLab, a fabless microelectronic company. It is the first low-cost low-power RF front-end solution in the world. It also has 4 channels supporting all GNSS systems and bands.

GNSS receivers are electronic devices that receive and process signals from a GNSS satellite. These signals used to provide information about receiver’s position,velocity, and time.

NUT4NT has two different working modes. The first uses dual inputs and acts as a centimeter level precision positioning tool, without the need of high quality antenna. The other mode uses the four inputs and provides an array antenna processing system to simply reduce interference and noise.

Dual Inputs Mode (Left) - Four Inputs Mode (Right)
Dual Inputs Mode (Left)   –   Four Inputs Mode (Right)

Hardware and software specifications of NUT4NT:

  • Receiver chip: NT1065
  • USB 3.0 controller: CYUSB3014
  • Clock rate: 10 MHz
  • RF inputs: two or four, depending on board option
  • RF inputs referred Noise Floor: 1 dB
  • ADC resolution – two-bit
  • ADC frequency – up to 99 MHz
  • Samples transfer – continuous full stream, from 20 to 100 Mbytes/sec
  • Power: 5V @ 0.5 A from USB or external adapter
  • Size: 70x50x20 mm (early board) / 77x122x25 mm (single board)
  • All GNSS systems: GPS, GLONASS, Galileo, BeiDou, IRNSS and future
  • All GNSS band: L1/L2/L3/L5, G1/G2/G5, B1/B2, E1/E5 and future
  • Four-channel synchronous reception for antenna array processing
  • Signal dumper (grabber) software
  • Spectrum analyzer software
  • NT1065 configuration software
  • Supports libusb API
  • Supports native Cypress driver API
  • Software for Windows, Linux, and potentially all other OS’s with libusb

There are two options of NUT4NT boards, the Early Board and the Single Board.

Early Board is for $399 and there are only limited boards to order through the crowdfunding campaign page. It consists of two separated boards: the base board, which has the USB 3.0 controller, and NT1065 submodule board.

Single Board will be available later as a future plan, and it is said to have  only one board instead of two.

NUT4NT Early Board
NUT4NT Early Board

NUT4NT is an open source project. Software sources are available on github and the hardware’s documentation will be available soon.

More information and details about the product with many accessories are reachable on the product crowdfunding page.

5 Tips on designing RF PCBs

Michael Ossmann shared some of his practical experience and insights in designing RF PCBs, Michael designed a lot of RF PCBs like HackRF One, which is an open source SDR (Software Defined Radio) platform.

Michael tips don’t include talking about Smith charts, Q factor, S parameters …etc which need a lot of academic knowledge, instead we will take “the simple way” as he said in his presentation.

The presentation consists of three parts: 5 rules for RF circuit design, some examples from Michael’s boards and how to select the components for the RF circuit design.

Michael tipped us with his 5 rules for RF circuit design:five_rules

Rule One: Use Four Layers

It’s not obligatory to use 4 layers in RF design, “you can do 2-layer design but you better start reading” Michael said.  if you don’t like to do an advanced RF study of your circuit, then use 4-layer design and follow the signal stack below.

rule1

Rule Two: Use Integrated Components

Always try to find an integrated component that meets your application. for example, use transceiver ICs like: CC2650, CC1310, ADF7242, AT88RF215, nRF24L01+… etc.
Also use passive components like filters in a shape of integrated component which is much easier than design a discrete one.

Rule Three: Use 50 ohm everywhere

The reason to use 50 ohm is to do impedance matching. This include microstrip impedance calculation to know it’s resistance and Michael showed us how to calculate that using online tools.

Rule Four: Follow The Manufacturer recommendations

Some times, the manufacturer will provide you with a reference circuit to match the impedance of output to 50 ohms, just follow this circuit!

rule4

Rule Five: Route RF First

Keep RF traces short and direct and keep other signals away from RF.

Via: hackaday

Inverter crystal oscillator

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Vasily Ivanenko build some discrete chip oscillators with 74HC series logic gates and tests them on his oscilloscope. He writes:

In numerous RF synthesizer chips lies an inverter with input and output pins for making a reference crystal oscillator clock. I built some discrete chip inverter xtal oscillators with 74HC series logic gates to better examine them. You’ll quickly recognize the oft-used Pierce oscillator topology with 1 trimmer capacitor to tweak the fundamental frequency which might vary from factors like crystal aging and gate, crystal, crystal holder + board reactances. I determined the 27 pF and trimmer cap values through experiments and measures.

Inverter crystal oscillator – [Link]