With IPHost Network Monitor you can run simple snmp requests against a Cisco device in your network.
cwrTxRfIndex
Cisco Wireless Tx Rf Index
1.3.6.1.4.1.9.9.136.1.3.1.1.5
This object specifies the index into the cwrRfTable identifying the antenna used for transmission. This index will be 0 if the associated transmit antenna is not present.
Back to CISCO-WIRELESS-IF-MIB MIB page.
IPHost Network monitor allows you to monitor cwrTxRfIndex on Cisco device via the SNMP protocol. Download IPHost Network Monitor (500 monitors for 30 days, 50 monitors free forever) to start monitoring Cisco firewalls right now.