The typical faults marked with XXI and XXII in the other graphs are not visible on first view. If you have a closer look you can detect the peak at 1500 MHz range. The bandwidth of this antenna covers all the four GSM bands, UMTS 2100 and even the 2400 MHz band for Wi-Fi, Bluetooth […]
Once more you will detect the typical faults marked with XXI and XXII. The bandwidth for the lower GSM bands is very small and the triangle marker 1 for the middle of the GSM 900 band is on the right side of the gap. There is a need for a matching circuit for sure. For […]
The graph shows the two faults marked with XXI and XXII again. The triangle marker 1 has left and rights a nice gap to cover the 6 dB bandwidth. It is already more than 250 MHz, and to cover GSM 850 plus GSM 900 we need 136 MHz only. Even the gap at GSM […]
The upper graph shows some interesting details. XXI and XXII are faults generated by the VNA. The peak close to 1100 MHz and 1500 MHz cannot be true. However, the peaks marked with XXI and XXII will be visible in the following graphs as well. Just ignore it and have a closer look on the […]
The four antennas at the picture below promise to be GSM quad band or even GSM quad band plus UMTS 2100. With a low budget VNA we let the cat out of the bag. The antennas have no chance. Our lie detector is called MiniVNA Tiny and will animate the antennas to tell us their […]