I have a circuit that incorporates a 40 channel InGaAs (IR) photodetector array (https://www.hamamatsu.com/eu/en/product/type/G8909-01/index.html). I have a TIA design using a LTC6268-10 first stage. However, because I require 40 of these, it is impossible to position all of the op-amps close to the photodetector.
The application potentially delivers quite low light input to the photodetector; I'm estimating ~1uA of photocurrent minimum. Fortunately, InGaAs photodiodes are less noisy than Si, but I'm concerned about noise pick-up on the traces from the wire-bond pads to the amplifier inputs.
As the Photodiode array is common-cathode, I can't connect the anode and cathode across the input terminals of the op-amps, which I believe would aid in reducing common-mode noise.
I'm wondering if I can lay the PCB traces to provide a coax-cable like performance, but I'm not sure how to go about achieving this.
Can anybody suggest some 'expert tips & tricks' that may help to retain my SNR?