Who would have thought that the AnaPico 100 kHz–20 GHz is built entirely with discrete components?

This is a Swiss-made AnaPico RFSG20 RF signal generator (100 kHz – 20 GHz, 50 Ω output), a professional lab/test instrument.

Multiple highly integrated PCBs, including the RF core board, control board, and interface board, interconnected via colour ribbon cables (Dupont wires) and coaxial cables (RF cables). On the boards, numerous RF chips (discrete components), shielding cans, pin-header connectors, and a small cooling fan (hanging on the panel) are visible. The overall layout is professional and compact, reflecting the high-frequency circuit design standard of the AnaPico RFSG20 signal generator.

AD9912A (from Analog Devices, packaged in Singapore) – a high-performance 2 GSPS 14‑bit DDS (Direct Digital Synthesizer) core chip. Its main role in the AnaPico RFSG20 is to perform precise frequency/phase/amplitude synthesis, generating stable sine‑wave signals from low frequencies up to GHz levels. It is one of the key source chips that enable the instrument’s 100 kHz – 20 GHz wideband signal output.

Key features:

Ultra‑high sampling rate (2 GSPS)

14‑bit resolution

Excellent phase noise and spurious suppression

Commonly used in high‑end RF signal generators, radar testing, 5G/microwave communication equipment development

Reconstruction filter on the AD9912 evaluation board.

The core main control + RF synthesis PCB of the AnaPico RFSG20, built around the AD9912A DDS chip, paired with a 100 MHz temperature‑compensated crystal oscillator (TCXO), multiple Analog Devices op‑amps/comparators, several RF amplifiers and mixer chains. Signal input/output is achieved through SMA and coaxial connectors, forming a complete low‑phase‑noise wideband signal generation and conditioning chain.

Output filter.

The three large metal shield cans shown in the picture have deliberate openings/cutouts (marked with red and white boxes). This is a common precision design on RF PCBs:

Purpose: to allow test probes or debugging fixtures to directly contact critical internal RF nodes (such as signal test points, power rails, control lines) for factory tuning, performance verification, and after‑sales maintenance, without having to remove the entire heavy shield can each time.

Effect: it balances electromagnetic shielding with testability – preventing high‑frequency internal signals from radiating outward while preserving necessary “inspection windows”. This “semi‑open shielding” approach is common in high‑end RF instruments (like the AnaPico signal generator) and demonstrates professional design with practical serviceability.