I am designing LF passive RFID transponder chip for animal tagging applications (ISO 11784/11785) . The operating frequency is 134.2K hz . Basically the reader has 50 Ohm impedance and due to inductive coupling , the chip is powered on. For this purpose , I have to match the input impedance of chip ie 50 Ohms , this will produce 300mV at input of chip at 10cm distance (10dB power). My matching network should be as such to have an input impedance of 50 Ohm . So i am stuck at RF-DC part of this chip. It includes the matching network followed on by a dickson multiplier. The dickson multiplier gets , lets say , 300mV at input , and after 6-7 stages , it multiplies and provides 1V at output . But as soon as i connect some load (an LDO) to it , the voltages drop down , I dont have enought current at output of Dickson multiplier. Why is it happening ?
I am using TsmcN65 nm technology
I don't think there's a significance of 50 ohm impedance matching for LF RFID design. Receiver input should be high impedance, coil can be designed for optimal power supply. I would refer to design of commercial RFID chips for this standard in the first place.