/!\ Vorläufig / Preliminary, work in progress /!\

Translate (Übersetzte) with Google

/!\ If you mouse click on a picture it will be expanded. You can go back to the web page with the back arrow of your web browser.

RF Attenuator Digital

In order to measure easier the response curve of RF modules I bought this 0.5 dB step digital attenuator. See the picture on the right.

The 30 dB version is the best buy, to measure up to 2.4 GHz. Now there is a new updated version with 0.25 dB stepping, see at the links.


There are 3 Models:

The Features are:

  1. the operating frequency: LF - 3 GHz
  2. the attenuation adjustment range (Model): 0-30 dB, 0-60 dB, 0-90 dB step
  3. the attenuation step: 0.5 (dB)
  4. insertion loss: ≤ 3.5 dB
  5. standing wave ratio: ≤ 1.4
  6. Attenuation accuracy: ± 1 dB max.
  7. Rated input power: 1 W = 30 dBm
  8. Connector type: SMA
  9. Temperature range: -10 ℃ ~ +50 ℃ (operation) -40 ℃ ~ + 70 ℃ (not running)
  10. Overall dimensions: 55 X 40 X 16.5mm
  11. Weight: 57g
  12. Input and output impedance: 50 Ohm
  13. The attenuation value is stored in EEPROM (found out)


The operation:

Remote Control (corrected):


After opening the housing, I realized that the labels of the IC's was sanded off. See the photo above.

Fortunately there are only some attenuator IC's on the market. When you search the internet for PEREGRINE_HF-Switch-PE4302_EN.pdf you will find the data sheet. There is also a second source F1912 from company Renesas. Because of the 10 KOhm resistor on pin 3 it could be only the PE4302, see page 5 of the data sheet.

/!\ Considering that, it makes only sense to buy the 30 dB version. If you need more attenuation add fixed value attenuators.


VNA Measurements

2020-11-13 Now having a Vector Network Analyzer nanoVNA-V2 (480x320 pixel display) which works up to 3 GHz, I wanted to measure the frequency response of the new 30dB attenuator Link 3.

See the screen shot on the right, which shows a measurement from 0.01 to 3000 MHz.

The nanoVNA-V2 was calibrated for the same frequency range.

It can be seen, that up to 1.5 GHz the frequency response is linear (CH1 LOGMAG).

With that in mind it is hardly understandable the advertising with a frequency range of up to 3 GHz.


At an attenuation of 30 dB the frequency response looks very similar to the 0 dB attenuation.

See the screen shot on the right.









In order to see, if the frequency response is linear in the range of 0.01 to 1500 MHz I measured several points and created a spreadsheet in order to see, if the amplitude loss over frequency can be compensated by a formular.

The attenuation setup was 0 dB.

Yes, the function is about 1.5 dB loss per GHz.

f(x) [dB] = -0.00147 * x - 1.252 dB .








/!\ There is no DC blocking (about 70 Ohm, IN to OUT), so avoid DC voltage at the input.

At the maximum attenuation of 31.5 dB, you have an Attenuation Error at 2.4 GHz of about 1 dB. See the data sheet for more details.

The 30 dB version is the best buy, if you measure above 500 MHz.

Now there is an updated version (0.25 dB step) on the market, probably with the IC PE43703, see at the links. This IC is now obsolete and replaced by the IC PE43713.

  1. aliexpress.com, 3G digital program-controlled attenuator 30DB 60DB 90DB step 0.5DB OLED display

  2. Datasheet PE4302

  3. 6G digital programmable attenuator 30DB stepper 0.25DB OLED

  4. dBm-Watt-Voltage table

  5. dBm Voltage calculator

  6. dBm to Watt calculator

up to top

Contact Email, please enter your Email address

/!\ The entered Email address will not be published, or given away.

Comment this page
Are you human?

List of pages in this category:

-- RudolfReuter 2020-05-26 17:52:29

Go back to CategoryAmateurRadio or FrontPage

RF-Attenuator-Digital (last edited 2021-06-06 16:02:28 by RudolfReuter)