MULTIBAND ANTENNA FOR PORTABLE RADIO DEVICE Russian patent published in 2001 - IPC

FIELD: antennas and coils for feeding multiband antennas. SUBSTANCE: first coil 110 resonating at first frequency and second coil 120 resonating at second frequency are coupled with rectilinear conducting part 140 of antenna 130 to obtain multiband antenna. First and second coils 110 and 120, respectively, are to be preferably of different axial length and circumference; they should be wound in opposite directions and placed coaxially to antenna 130. Additional coils may be introduced to provide for using additional frequency bands and also use may be made of top coils 150 to obtain multiposition design. EFFECT: compact design; enhanced gain of antenna sometimes even higher than that of single-band ones. 20 cl, 5 dwg