with ADP7104 10 GHz 10-bit 32 Gsps digitizers
- Real-time ADC equalization and channel de-embedding
- Precise channel synchronization and timing alignment
- 100+ Gpoint acquisition memory per 32 Gsa/s channel
- Fast cross-correlation signal processing
Highly accurate Cross-correlation detection for time difference of arrival (TDOA) for wide bandwidth modulated signals is achieved using a Guzik ADP7104 32 GS/s digitizer.
The accuracy is ensured by real-time ADC equalization, precise channel synchronization, channel time alignment and signal processing (averaging and interpolation by FFT)
The result of interpolation is shown by blue curve and compared to 32 GS/s raw samples shown by red curve in Fig. 1.
For 1 us 4 GHz wide linear FM signal at 4 GHz center frequency, going through 29 GHz mmWave up/down converter path, the system can achieve TDOA standard deviation of 2 ps even at SNR = 0 dB.
Fig.2 shows TDOA standard deviation measured over 3000 individual 1 us FM pulses mixed with additive white Gaussian noise.
Fast cross-correlation averaging using Guzik ADP7104 digitizer improves SNR and achieves very high TDOA accuracy for all real-life scenarios.
For example, using average cross-correlation for 50 repetitions of 1 us long FM signal up/down converted to 29 GHz resulted in less than 0.3 ps TDOA accuracy.
The accuracy of the TDOA measurement was verified by using two identical channels of 65 Gs/s Keysight M8195A AWG and setting programmable channel delay between CH1 (reference) and CH2 (mmWave).
The delay was measured with accuracy better than 0.3 ps after 50 cross-correlation averages.
The system setup is shown below with reference channel path in yellow and mmWave channel path in green color:
Below please find the live software demo of the measurement:
Note: Measurement results provided are representative and performed under ideal conditions without “Pre-Corrections” at +25˚C ambient temperature. The results are not warranted specifications.
Please contact Guzik Technical Enterprises to find out more about the wideband TDOA solution here: firstname.lastname@example.org