AN2731 Freescale Semiconductor / Motorola, AN2731 Datasheet - Page 24

• Manufacturer Part Number: AN2731
• Description: Compact, Integrated Antennas: Designs and Applications for the MC13191 and MC13192
• Manufacturer: Freescale Semiconductor / Motorola

Design Examples
8.4
An experimental full-wave loop, loaded with chip inductors, is shown in the following figure. Gain is
about –3 dBm, which is much better than a chip antenna of comparable performance.
8.5
An experimental quarter-wave slot antenna was tested with the outline as shown in the following figure.
The antenna was built using a Pertinax PCB, which is not recommended due to high losses. The antenna
still performed reasonably well. A design using FR-4 and a milled slot is recommended.
24
Loop Antennas
Slot Antenna
Length
Width
Slot Length
Slot Width
Feedpoint
Impedance
Side Length of Loop = 14 mm
Track Width
Loading Coils
Impedance
Figure 25. Experimental Quarter-wave Slot
Figure 24. Experimental Full Wave Loop
Compact Integrated Antennas, Rev. 1.2
= ~ 200 ohms (Symmetrical)
= 26 mm
= 2.7 mm from shorted end
= 5 mm
= 23 mm
= 0.6 mm
= 2 x 3.9 nH
= 200 ohms (Symmetrical)
= 3x3 mm
Freescale Semiconductor