PG-TIA-2 IF Amplifier

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This is a new version of the PG-TIA with isolation pads for gain-setting resistors and wider component spacing.

The performance of a receiver or transmitter depends on careful impedance matching between its sub-systems: its mixers, filters, and amplifiers. Mismatches can cause loss of signal strength, inter-modulation distortion, and deep ripples in the audio passband that can make human speech hard to understand.

A termination-insensitive amplifier (TIA) such as this one always presents a 50Ω impedance at both its input and output ports, providing a stable and predictable impedance to whatever it’s hook up to. This simplifies the design of the mixers, modulators, product detectors, and filters these TIA amplifiers serve in a complete radio system. The circuit on which this broadband TIA IF amp is based was devised by Wes Hayward, W7ZOI, and Bob Kopski, K3NHI.

This version of the PG-TIA

The TIA Broadband IF Amp has these features:

• Input and output port impedance is always 50Ω and does not pass through or “telegraph” to the other port.
• “Programmable” gain from 7 to 24dB.
• Gain-setting resistors easily swapped on isolation pads printed on PCB (similar to “Manhattan” style).
• Useful from 1 to 30MHz (with slightly-lower gain above 14MHz).
• Uses 12VDC power.
• PCB pads for edge-style SMA connectors (also usable for direct solder connection).
• Mounting holes for 4-40 (M3) screws.
• 1.58″ (4cm) long, 0.84″ (2.6cm) wide.

The PG-TIA-2 is available as a bare PCB, a kit of PCB and components (SMAs not included), or as a fully-assembled and tested unit (SMAs not included).

Schematic diagram (PDF)

User’s guide (PDF)

Github Repository