WiFi antenna

This is my ongoing project for Wifi Yagi Antennas made with the milling machine. In other words this not complete

Frequency Range: 2400MHz - 2483MHz

Center Frequency and bandwidth estimate

Band Width: 83MHz

Frequency Range with error included: 2399.88MHz - 2483.13MHz

Bottom fequency deviation with error: $c/(c/F+E)=BFD=2399.88MHz$, $F=2400MHz$

Top fequency deviation with error: $c/(c/F-E)=TFD=2483.13MHz$, $F=2484MHz$

Milling machine resolution: $E=6.35*10^{6}m$

Speed of light: $c=2.998*10^{8}m/s$

Band Width: $TFD-BFD=83.25Hz$

Average error over frequency range: 126KHz

Center Frequency: $(TFD-BFD)/2+BFD=2441.63MHz$

Based on the above the yagi should be built around the frequency 2441.63MHz with a bandwidth of at least 83.25MHz

Possibilities

Yagi

simple, obvious, designs available; expect 6-9db gain for 3 elements

Log periodic

greater bandwidth; expect 10-30db gain for 5-7 elements

biquad

needs a reflector spaced correctly in 3d [1]

conical

can a pcb spiral be stretched into a cone?

colinear

high gain omni; could do colinear slots on a pcb

Cisco article on wifi antennas

Designs

Yagi Model 1

Thanks to Hao Dong for running this simulation!

PCB

31mil 0.5oz. Copper

PCB size

2in by 2.4in

Yagi elements

6

|S11|dB < -5.66dB from 2.412 to 2.484GHz

VSWR < 3.18 from 2.412 to 2.484GHz

Gain

8.089dB@2.412GHz

7.863dB@2.432GHz

7.652dB@2.452GHz

7.535dB@2.472GHz

7.531dB@2.484GHz

See also

• wifi
• antenna links

External Links

• Yagi calculators
• http://www.wa5vjb.com/ pcb antennas (frequency ranges not quite right)
• wifi cards and antenna pictures (PDF) look at pages 12, 13