View source for PE4302 RF Attenuator

[[file:PE4302_P1833-720px.jpg]]

== Features ==

[[File:RF_Atten-Front-01.jpg]]

[[File:RF_Atten-Rear-01.jpg]]

* [http://www.west-l.com/uploads/tdpdf/yqperegrine_hf-switch-pe4302_en.pdf PE4302] RF attenuator module
* Parallel immediate mode
* Program control gain attenuation range is from 0 to 31.5dB
* Bandwidth 1MHz to 4GHz

=== Specifications ===

* Power Supply Voltage
** 2.7-3.3 VDC - 3V typical
** Typical current 5mA
* Program control gain attenuation range
** 0~31.5DB
** 10K pull down resistors to ground
** Step size: 0.5DB
* Input/Output Impedance
** 50 ohm
* Bandwidth
** 1MHz~4GHz 
** Attenuation value will differ under different frequency
* Max Input power (50Ω)
** +30 dBm
** 1W = 7.1V RMS
* Connectors
** SMA-female

== My Build ==

* A lot of designs use Arduino/OLED, etc to control the card - unnecessary
** Could add noise from OLED
** Doesn't need to switch too often
* Mount in [https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313&_nkw=80+50+20+project+enclosure+plastic&_sacat=0&LH_TitleDesc=0&_odkw=80mmx50mmx20mm+project+enclosure+plastic&_osacat=0 small 80mm x 50mm x 20mm project box]

[[file:PE4302_P1833-720px.jpg]]

[[file:PE4302_P1831-720px.jpg]]

[[file:PE4302_P1832-720px.jpg]]

* SMA connectors
** Board connector for one SMA
** Short cable male SMA to SMA female bulkhead SMA for other end
* PE6402 remove straight header, replace with right angle connector over card
* [[Mini360 Adapter Board]] for wide input voltage range
** 4.75-23V input
** 3V output
** Concern over EMI?
** Right angle connector 2x3 min
* Use [[SWLEDX8]] to control attenuation selection
** Right angle 2x10 under card for low profile installation
** Use SW1-SW6 switches (centered horizontally on card)
** Digital Input High 0.7xVDD in V = 2.1V
** Using 1.2K-1.5K pullup to counter the 10K pulldowns on the card = 2.6V
** When switch is on/low - 3V / 1.5K = 2 mA
** Adds to current 2 mA x 6 = 12 mA when all switches are low
** Use D7 for power indication
*** Vf = 1.8V, 3V-1.8V = 1.2V, 3 mA for lower light level - use 470 ohm resistor
* Cabling
** 1x7 pin PE4302 connector (Use 1x8, ignore 8th pin)
** 2x10 Dupont connector for [[SWLEDX8]]
*** Ground, power to D7 LED, 6 switches
** 2x3 Dupont connector with pins from [[Mini360 Adapter Board]]

[[file:SWLEDX8-720px.jpg]]

== Measurements ==

* NanoVNA
** Sweeping from 1-300 MHz
* All switches set to GND
* Approx 2 dB insertion loss
* S21 Gain zoomed in

[[file:SW_All_0s-ZoomedIn.PNG]]

* All switches set to GND
* Min -1.2 dB insertion loss

[[file:SW_All_1s.PNG]]

== References ==

* [https://kv4qb.blogspot.com/2019/04/63-db-step-attenuator.html DuWayne's Arduino based attenuator]
** Hackaday project page
* [https://www.psemi.com/products/family/rf-attenuators Peregrine Semiconductor's page] - Chip maker
* [https://github.com/tswfi/PE4302_Attenuator PE4302 tswfi] - Simple attenuator built with PE4302 and Arduino "pro micro".
** [https://github.com/tswfi/PE43xx PE43xx Arduino Library]