**3. Simulation results**

230 VLSI Design

Wp 0.16366496 Lp 0.1272564 Wp1 0.01742811 Lp1 0.0165981

Patch antenna array sizes (m)

Wp2 0.1272564

Fig. 3. Geometry of the antenna array (T shape), with cuts on its corners.

Location, (m).

Table 6. The feed point and shorting pin location.

4), but there were some problems in each one.

The feed point and shorting pin location are shown in Figure 3 and its coordinates in Table 6.

Before to obtain the geometry shown in Figure 3, other two geometries were realized (Figure

(a) (b)

Fig. 4. First geometries implemented (L shape) and (b) irregular cuts.

Feed point Shorting pin X 0.035 X -0.0025 Y -0.0595 Y -0.04175 Z 0 Z 0

Table 5. Sizes of the patch antenna array with cuts.

The 3D far electrical field magnitude patterns as a function of frequency are shown in Figure 5. The electrical far field components, in polar coordinates are shown in Figure 6.

Fig. 5. Radiation pattern of the far electrical field magnitude at (a) 70.98 MHz and (b) 194.8 MHz.

Fig. 6. Components of the electrical Far Field.

As it can be observed from Figure 5a, the radiation pattern at 70.98 MHz, corresponds to an omnidireccional antenna, with horizontal polarization, while in Figure 5b, the radiation pattern at 194.8 MHz corresponds to a directive antenna directed on the X-axis, with maxima on both directions.

Low Cost Prototype of an Outdoor Dual Patch Antenna

**4. Experimental and practical results** 

be recognized that our laboratory equipment is limited.

of -18.4 dB.

of the CIICAp building.

Array for the Openly TV Frequency Ranges in Mexico 233

Fig. 9. Reflection coefficient magnitude centered at 194.8 MHz, with a minimum return loss

On the base of simulation results, the prototype was fabricated on FR-4 and coupled with coaxial cable of 75 ohms (see Figure 10). In Figure 11, the spectrum analyzer displays the two ranges frequencies received with the prototype: (58.75 MHz, 109.37 MHz) and (155.5MHz, 238.75 MHz), the maximum peak response has a value of -38.5 dBm. Even the primary results shown here, more experimental analysis must be still realized, but it must

(a) (b) Fig. 10. (a) Patch antenna array prototype. (b) Prototype mounted on a PVC base, outdoors

The received range frequencies for the case of a rabbit-ear antenna are shown in Figure 12, where it can be also noted two frequency ranges: (88 Mhz, 108.25 MHz) and (171.25MHz, 182.5 MHz), with a maximum peak of -50 dBm. From these photographs, the bigger

The Reflection Coefficient magnitude of the antenna is shown in Figure 7, where the peaks of response are located at 70.98 MHz and 194.8 MHz, very near to the selected design operation frequencies (71 MHz and 195 MHz, which correspond to the central frequencies of the two sub-ranges). A zoom at both frequencies is presented in Figures 8 and 9.

Fig. 7. Reflection coefficient magnitude.

Fig. 8. Reflection coefficient magnitude centered at 70.98 MHz, with a minimum return loss of -9.86 dB.

The Reflection Coefficient magnitude of the antenna is shown in Figure 7, where the peaks of response are located at 70.98 MHz and 194.8 MHz, very near to the selected design operation frequencies (71 MHz and 195 MHz, which correspond to the central frequencies of

Fig. 8. Reflection coefficient magnitude centered at 70.98 MHz, with a minimum return loss

the two sub-ranges). A zoom at both frequencies is presented in Figures 8 and 9.

Fig. 7. Reflection coefficient magnitude.

of -9.86 dB.

Fig. 9. Reflection coefficient magnitude centered at 194.8 MHz, with a minimum return loss of -18.4 dB.
