The 70600A module functions as a 0–22 GHz tuneable bandpass filter, which can be used to measure small magnitude signals adjacent to higher power signals, and to reduce multiple and image frequencies and other unwanted mixing products. When tuned between 50 kHz and 2.9 GHz, it acts as a low-pass filter, and when operating between 2.7 GHz and 22 GHz, it uses a Yig Tuned Filter (YTF) to act as a bandpass filter centred on the desired frequency.
As an integrated part of the HP70K system, band selection and filter tuning is controlled as part of the sweeping operation. Bypass control and calibration offsets are automatically configured to allow for consistent measurement units. A 70600A is placed to the immediate right hand side of an RF Input Module, and can be placed before, after or between pre-amplifier modules.
Inside the 90600A
The major components visible on this side are:
A2 — 6 dB Attenuator
A3S1 — RF Switch 1
A4S2 — RF Switch 2
A5S3 — RF Switch 3
A6S4 — RF Switch 4
A7 — Switch Driver
A8 — Input Attenuator
A9 — Yig Tuned Filter
A10 — Limiter
A11 — Low Pass Filter
The front panel RF INPUT is routed to the Input Attenuator (A8), then on to RF Switch 3 (A5S3). RF Switch 3 is either connected through to RF Switch 1 (A3S1), when in bypass mode, on to the front panel RF OUTPUT, or to RF Switch 4 (A6S4), which switches between the Yig Tuned Filter (A9) or the Limiter (A10) and Low Pass Filter (A11). The outputs from these two paths are connected to RF Switch 2 (A4S2), which is then connected to RF Switch 1 (A3S1), and when not bypass mode, on to the front panel RF OUTPUT.
The major components visible on this side are the YTF Control board. The rear panel TUNE + SPAN INPUT is connected to the YTF Control board near the centre of the photo.
The signal flow can be seen in the below block diagram:
Here we can see the RF switching path and the organization of the YTF Driver (A12).
Interesting Experiments
Given that a tuneable bandpass filter is a very useful component, it would be interesting to test if the 70600A can function when the module is not configured as a slave to a 70900.
Module Resources
Operating Note:
Installation and Verification Guide:
Service Guide:
