I am work for a company which is developing electronics for use on weather balloons. These balloons typically reach 80,000 to 100,000 ft during flight and experience severe turbulence on the way up and down. The products we develop are recovered and when there is an antenna failure the unit is lost.
Antennas Used in the Past:
The original antenna we was a Maxrad MTO 8903 PT patch antenna which worked great, but went out of production (with what I can gather). This was a Patch Antenna with 2.5 to 3 db in gain, 3 inches in diameter and .25 inches tall.
The new antenna we have been using is HG905RD-RSP rubber duck antenna, which has been breaking in many different ways during flight (The most common is the plastic housing breaking off of the metal connector.) This is a 5 db antenna which works great when it is not broken during flight.
Problem Diagnosis for Rubber Duck Antenna:
There are two main factors for the failure of the Rubber Duck Antenna: 1) Length of antenna allows for lines and payloads to damage the antenna 2) The cold temperatures experienced during a flight which are many times below -40F, which causes the plastic to break.
Antenna Solution Needed:
Both of these factors were not a problem for our low profile patch antenna, because there was nothing to get lines caught on and if a payload hit the antenna there was almost nothing to break. We never had a patch antenna fail.
I dont have much experience with antennas but I have had difficulty finding a patch type antenna with more than unity gain. The other limitation we are dealing with is there is no ground plane for the antenna and we want to make sure we are not adding to much weight to the overall module.
Desired Technical Specifications:
Commercial Off the Shelf (COTS)
Frequency Band: 900 MHz ISM Band (902-928 Mhz)
No Ground Plane needed
At least 2.5 db in gain
Less than 3 inches in diameter
Reverse SMA Connector (not critical we can always make a different cable)
I look forward to you feedback and insights
Antennas Used in the Past:
The original antenna we was a Maxrad MTO 8903 PT patch antenna which worked great, but went out of production (with what I can gather). This was a Patch Antenna with 2.5 to 3 db in gain, 3 inches in diameter and .25 inches tall.
The new antenna we have been using is HG905RD-RSP rubber duck antenna, which has been breaking in many different ways during flight (The most common is the plastic housing breaking off of the metal connector.) This is a 5 db antenna which works great when it is not broken during flight.
Problem Diagnosis for Rubber Duck Antenna:
There are two main factors for the failure of the Rubber Duck Antenna: 1) Length of antenna allows for lines and payloads to damage the antenna 2) The cold temperatures experienced during a flight which are many times below -40F, which causes the plastic to break.
Antenna Solution Needed:
Both of these factors were not a problem for our low profile patch antenna, because there was nothing to get lines caught on and if a payload hit the antenna there was almost nothing to break. We never had a patch antenna fail.
I dont have much experience with antennas but I have had difficulty finding a patch type antenna with more than unity gain. The other limitation we are dealing with is there is no ground plane for the antenna and we want to make sure we are not adding to much weight to the overall module.
Desired Technical Specifications:
Commercial Off the Shelf (COTS)
Frequency Band: 900 MHz ISM Band (902-928 Mhz)
No Ground Plane needed
At least 2.5 db in gain
Less than 3 inches in diameter
Reverse SMA Connector (not critical we can always make a different cable)
I look forward to you feedback and insights