WikiSysop: Created page with "This document outlines the construction of a Cloverleaf antenna for the 902-928MHz ISM band. Final result of the CL build. ==Summary== A..."

2015-08-07T00:44:39Z

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This document outlines the construction of a Cloverleaf antenna for the 902-928MHz ISM band.

[[File:Cloverleaf.jpg|thumb|right|Final result of the CL build.]]

==Summary==
A cloverleaf antenna is an omnidirectional, circularly polarized antenna, constructed of three 105 degree arcs spaced 120 degrees apart, with each straight leg measuring a quarter wavelength. The antenna was built using the instructions here: http://www.rcgroups.com/forums/showthread.php?t=1388264

The antenna is soldered directly to a short length of RG-316 coax, with a SMA male connector at the end.

The total build time for this antenna was approximately 45 minutes.

===Bill of Materials===
{| border="1"
|style="text-align:center;" |'''Part'''
|style="text-align:center;" |'''Quantity'''
|style="text-align:center;" |'''Unit Cost'''
|style="text-align:center;" |'''Total Cost'''
|style="text-align:center;" |'''Source'''
|-

|SMA Male Connector
|1/5
|style="text-align:right;" |$2.51
|style="text-align:right;" |$0.50
|[http://www.dealextreme.com/p/sma-1-5-diy-connector-plug-5-pack-5132 Dealextreme]
|-

|RG-316 Cable
|5"/50'
|style="text-align:right;" |$16.05
|style="text-align:right;" |$0.13
|[http://www.ebay.com/sch/m.html?_nkw=rg-316+50&_sacat=0&_odkw=rg-316&_osacat=0&_armrs=1&_ssn=rfbat eBay]
|-

|Pencil
|1
|style="text-align:right;" |~$0.50
|style="text-align:right;" |~$0.50
|Office Supply Store
|-

|18ga. Solid Core Wire
|39"/100'
|style="text-align:right;" |$6.89
|style="text-align:right;" |$0.23
|[http://www.radioshack.com/product/index.jsp?productId=2036274 Radio Shack]
|-

|'''Total Price'''
|
|
|style="text-align:right;" |'''~$1.36'''
|
|-
|}

==Photos==
<gallery widths=180px heights=120px perrow=4>
File:Cloverleaf.jpg|Cloverleaf Antenna
File:Cloverleaf_Top.jpg|Top-down view of CL
File:Cloverleaf_Side.jpg|Side view of CL
File:Cloverleaf_Single_Coax.jpg|Semi-prepared coax and single "blade" of Cloverleaf/SPW
</gallery>

==Results==
[[File:Cloverleaf_S11_VSWR.png|thumb|640px|center|Post-optimization return loss (left), and VSWR (right).]]

After tweaking the angles of the antenna, the VSWR is below 1.2 over the 900MHz ISM band (902-928MHz) with a VSWR of 1.08 at 910MHz, resulting in an efficiency of >99.3% (calculated by the formula Power % = 100 * (1 - ((SWR-1)/(SWR+1))<sup>2</sup>). The antenna weighs 15.9g.

Cloverleaf - Revision history

WikiSysop: Created page with "This document outlines the construction of a Cloverleaf antenna for the 902-928MHz ISM band. Final result of the CL build. ==Summary== A..."