Have you considered a switched antenna array? This may have the same wavelenghth geometry issues as other types. RF switch cycles through the antennas to an FM receiver - which compares the phases differences. I think Ramsey even has a kit for this.chandramanikumar said:hey people i have to design a highly directive antenna for a direction finding device operating in the 100 to 500 MHz band, can u plz help me out on this.
Al42 said:A Yagi that's directional over a 5:1 frequency range? Yagi's turning over in his grave. To maintain directivity the antenna must maintain spacing and element length - in wavelengths - and that's not possible over that great a range.