My problem is mybe off topic, but I will ask:I want build up a GSM detector - microstrip PCB resonator + detector diode. System was working, but haven't enough sensitivity. I tried with lot of different HF diodes, (Schottky 1N5711 and special detector diodes from HP - HSMS2850 series).
After that I purchase a GSM-detector toy, which has very simple electronic in self, but on board stay a HF diode, which has about 5x higher sensitivity than HSMS2850. That diode is a simple glass diode (like 1N4148) and stay on it only "H". Which type can be that diode? Can somebody help me to found proper detector diode for 900MHz detection?