1 Supervisory and 4 Coherent Channels

1 Clock Card (CLK_Card) is used for the realisation of the entry level receiver. Such architecture enables the configuration of up to 5 receiving channels. 4 channels are synchronised by the Buffer Clock 5PB1104 and 1 channel is synchronised directly by the TCXO 28.8 MHz (see the block-diagram for more details).
The 28.8 MHz output can be used for the connection of one or more single-channel receivers (using HF-adapter) or EXP_Card for the middle level configurations.

  • ADC Resolution: 8 bit
  • Clock: 28.8 MHz
  • Temperature compensated oscillator (TCXO) : 2 PPM (2 PPM initial offset, 0.5-1 PPM temperature drift). Higher precision, e.g. 0.1, 0.5, 1.0 ppm, available  on request.
  • Female antenna port : SMA
  • R820T2 tuner: 24 MHz –  1766 MHz (direct sampling with lower frequencies possible)
  • Operation temperature: -10 to 60 ˚C
  • USB powered bias tee: 4,5V
  • Noise figure: 3.5 dB @ RF_IN
  • Noise floor: –60 dBm
  • Dimensions (RTL-SDR, CLK_CARD, EXP_CARD): 67 x 25 x 6 mm

Direction finding system (configuration: 4+1)

The Supervisor has following functions:

  • power supply to the clock card
  • I2C interface to the clock card and noise generator
  • The Supervisor can be used as a normal receiver as well

The Supervisor can be tested by starting a SDR-programm, like rtl_fm or SDR#. Tune this receiver to the FM-Station and you have to get FM-signal without any additional steps or configurations. Single channel receivers have a common clock that is distributed from the clock card; you need to power on the supervisor in order to provide the power supply to the clock card. If the clock card is off, it cannot generate clock. Therefore, the system will not work.

Single-board multi-tuner receivers

  • Frequency Range: 24 MHz – 1.7 GHz
  • ADC Sample Rate: 25 MSPS
  • up to 8 MHz spectrum (10 MHz on request with an alternative tuner) per tuner
  • Bit Depth: 8 bits – 4 Tuners on board; 12 bits-16bits – 2 Tuners on board

All channels on the board are sampled synchronously and have common clock (2 or 4 synchronous channels). External synchronisation is necessary only for the phase calibration. Multiple boards can be chained together with a common clock and an addtional I/Q-synchronisation. NOT A RETAIL PRODUCT.

Multi-tuner receivers with I2S output

Multi-channel I2S to USB

We have developed a technology that allows an unlimited number of I2S or other serial channels to be streamed into PC via USB 3.0 without using FPGA or XMOS chips. This technology is used in our Radio-monitoring solution where we can monitor more than 100 FM or DAB+ stations simultaneously. It is also possible to install 16/24/32-bit ADC with I2S-output or integrate a microphone array with I2S.

Future plans

It is possible to use this technology with automotive RF-tuners: STA709, STA710, TDA7707, TDA7708, Si476x, Si479x or LV25810PEB that provide digital I/Q-output via I2S. Typical such chips support about 500 kHz BW signal for further signal processing. All channels can be locked to a common clock and decode simultaneously and parallel. No need to use external synchronisation source if the number of channels does not exceed 30 channels. If there are more than 30 channels, it is necessary to use an external synchronisation source for the time-alignment of channels. Tuner PLLs are also locked to the common reference clock but due to PLL-implementation with the internal VCOs, PLLs are not phase-synchronised. It is necessary to provide an external synchronisation source and calibrate the phase after every reset or frequency change.
We evaluated the above mentioned components and decided for own development. Recently we developed a prototype of 25-channels per USB port (multi-usb synchronisation is also possible) receiver with a frequency range 85 MHz – 2.700 MHz (85 – 4.200 MHz using an alternative wideband synthesizer) and 32-bit, 2-channel, 768 kHz sampling, differential input A/D converter per channel. Please contact us if you have interesting application scenarios for such receiver.