0:00:07 Introduction: The video introduces the Heroic SA2200, a compact, 20 GHz real-time spectrum analyzer with FPGA-based signal processing and 100 MHz analysis bandwidth, powered and operated via USB-C.
0:00:37 Form Factor and Connections: It has a very tiny form factor, almost pocket sized. The SA2200 features a K-type connector for the RF input. Maximum input is 23 dBm with the amplifier off, and 10 dBm with the preamp on, with a 12V maximum DC input. It utilizes separate USB-C ports for power and data and includes auxiliary I/O and expansion connectors.
0:02:09 Datasheet Review: The reviewer highlights potential performance compromises due to miniaturization and cost reduction. Key specs:
Phase noise at 1 GHz, 1 kHz offset: -91.2 dBc/Hz (to be tested).
Spurious response: Typically -90 to -80 dBc, which may affect low-level signal detection.
Image rejection: 90 dBc typical with enhanced mode (slower sweep).
Displayed Average Noise Level (DANL): As low as -165 dBm (with max preamp gain, narrowest resolution bandwidth).
Sweep speed: 1.1 THz/s for resolution bandwidth > 1 MHz.
IQ sample rate: 8 ns time resolution, 100 MHz max bandwidth.
0:05:53 Teardown: The reviewer disassembles the device, revealing multiple stacked PCBs. Impressive mechanical design and assembly are required to fit the complex circuitry.
RF Front End Board: DC block, input switch for selecting preamplifiers (6-26.5 GHz and 100 MHz amps), programmable attenuator, pre-select filters (ceramic, not PCB-integrated), additional amplifiers, all before any frequency conversion.
RF Conversion Board: Contains the first frequency conversion stage. High-band input goes to a 6-26.5 GHz IQ mixer, driven by a 20 GHz synthesizer. Low-band input goes through more pre-select filters, a bidirectional mixer (possibly used for up/down conversion), and a unified IF output.
Mixed Signal Board: Final down-conversion and digitization. Contains switches, filters, two synthesizers (one for LO, one for ADC clock), a 12-bit 250 MSPS ADC, a programmable RF attenuator, and a mixer (400 MHz - 3.8 GHz).
Also has an Altera 10 PD programmable device, and an ARM processor.
Digital Processing Board: Contains a Cyclone IV FPGA, DDR memory, and a USB controller for data processing and output.
Power Board: Has separate board for power to keep it isolated from the rest.
0:18:25 Simplified architecture: RF input -> pre-amp -> pre-select filters -> 1st Mixer -> pass filtering -> second mixer -> IF amplifier, gain control -> ADC -> FPGA -> USB.
The GUI is freely downloadable and updated, offering extensive control.
The "Spur Rejection" setting significantly impacts sweep speed.
Initial preset has preamplifier on "auto"; reviewer recommends setting to "forced off" to protect the input.
Phase noise test at 1 GHz (using a clean reference) shows better-than-spec performance (-96 dBc/Hz at 1 kHz offset).
Spurious response test (using a filtered 3.2 GHz tone) shows spurs below -90 dBc, meeting the specification.
IM3 (intermodulation) test (using two tones at 9 GHz) shows significant improvement by adjusting reference level and gain strategy, demonstrating the importance of proper settings. The built in IM3 measurement shows IP3 of 38 dBm, 41 dBm after adjustment.
IQ streaming mode allows detailed analysis of unknown signals. Multiple, independent windows show spectrum, power vs. time, and IQ vs. time.
Analyzing a 14 GHz signal reveals amplitude shift keying (ASK) modulation, with a bit rate determined from the time-domain data. Frequency offset technique is used to visualize the modulation clearly.
Some aliasing is observed, with a buffer related bug also.
0:47:47 Conclusion: The reviewer is impressed overall, highlighting the instrument's capabilities, compact size, and software features. The importance of software understanding, hardware performance is noted, and a 40 GHz model is mentioned for the future.