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uwb:evb [2021/08/07 12:26] – [Omnidirectional UWB Antenna Design] neilhaouwb:evb [2021/08/21 23:56] (current) – [Omnidirectional UWB Antenna Design] neilhao
Line 13: Line 13:
   * UWB Front-End Design   * UWB Front-End Design
   * Omnidirectional/Directional UWB Antenna Design   * Omnidirectional/Directional UWB Antenna Design
 +
 +{{ :uwb:ultra_wideband_evaluation_board_system_overview.jpg?direct&900 |}}
 ===== Hardware Design ===== ===== Hardware Design =====
 ==== UWB Front-End Design ==== ==== UWB Front-End Design ====
Line 37: Line 39:
  
 ==== Omnidirectional UWB Antenna Design ==== ==== Omnidirectional UWB Antenna Design ====
-=== Symmetric Antenna  ===+=== Symmetric Antenna Candidate 1  === 
 +Symmetric Antenna Candidate 1 is a revised edition of Candidate 2. It also uses rectangular slot and attaching strip for size reduction [2]. This antenna is still printed on a 30mm*32mm PCB with desirable symmetrical radiation pattern. The bandwidth is expected to cover UWB Channels 2, 3,5 and 7. 
 + 
 +Sample 1 and Sample 2 are fabricated antennas with exactly same design. I used two samples for the consistency verification. 
 +{{ :uwb:uwb_symmetric_antenna_candidate1.png?direct&900 |}} 
 +{{ :uwb:uwb_symmetric_antenna_candidate1_s11.png?direct&600 |}} 
 +**Note:** __Red__ – Sample 1 Measured, __Pink__ – Sample 2 Measured, __Blue__ – Simulated  
 + 
 +The difference between the simulation results and measurement results is not only due to the accuracy of the simulation model. In the measurements of small antennas, the RF cable usually affects the performance of antenna under test greatly [2]. I reproduced this phenomenon by using different kind and different length SMA cables with the same VNA Tektronix TTR506A and VNA calibration kit. Notable difference of results was observed. 
 + 
 +**Radiation Pattern of YZ Plane** 
 +{{ :uwb:uwb_symmetric_antenna_radiation_pattern_3ghz_to_7ghz_candidate_1.png?direct&900 |}} 
 + 
 + 
 +=== Symmetric Antenna Candidate 2  === 
 +Rectangular slot notching onto the radiator and attaching strip to the radiator can reduce the size of UWB antenna [2]. This antenna is printed on a 30mm*32mm PCB with desirable symmetrical  radiation pattern. The bandwidth is expected to cover UWB Channels from 1 to 7 (3244.8Mhz to 6998.9MHz).
 {{ :uwb:uwb_symmetric_antenna.png?nolink |}} {{ :uwb:uwb_symmetric_antenna.png?nolink |}}
-Rectangular slot notching onto the radiator and attaching a strip to the radiator can reduce the size of the antenna [2]. This antenna is printed on a 30mm*32mm PCB with desirable symmetrical  radiation pattern. 
  
 == Antenna Parameters == == Antenna Parameters ==
 {{ :uwb:uwb_symmetric_antenna_parameters.png?direct&900 |}} {{ :uwb:uwb_symmetric_antenna_parameters.png?direct&900 |}}
 +
 == S11 == == S11 ==
 {{ :uwb:uwb_symmetric_antenna_s11.png?direct&600 |}} {{ :uwb:uwb_symmetric_antenna_s11.png?direct&600 |}}
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 3D @ 4GHz: 3D @ 4GHz:
 {{ :uwb:uwb_symmetric_antenna_3d_at_4ghz.png?direct&200 |}} {{ :uwb:uwb_symmetric_antenna_3d_at_4ghz.png?direct&200 |}}
-3GHz:+3GHz YZ Plane:
 {{ :uwb:uwb_symmetric_antenna_radiation_pattern_3ghz.png?direct&600 |}} {{ :uwb:uwb_symmetric_antenna_radiation_pattern_3ghz.png?direct&600 |}}
-4GHz:+4GHz YZ Plane:
 {{ :uwb:uwb_symmetric_antenna_radiation_pattern_4ghz.png?direct&600 |}} {{ :uwb:uwb_symmetric_antenna_radiation_pattern_4ghz.png?direct&600 |}}
-5GHz:+5GHz YZ Plane:
 {{ :uwb:uwb_symmetric_antenna_radiation_pattern_5ghz.png?direct&600 |}} {{ :uwb:uwb_symmetric_antenna_radiation_pattern_5ghz.png?direct&600 |}}
-6GHz:+6GHz YZ Plane:
 {{ :uwb:uwb_symmetric_antenna_radiation_pattern_6ghz.png?direct&600 |}} {{ :uwb:uwb_symmetric_antenna_radiation_pattern_6ghz.png?direct&600 |}}
-7GHz:+7GHz YZ Plane:
 {{ :uwb:uwb_symmetric_antenna_radiation_pattern_7ghz.png?direct&600 |}} {{ :uwb:uwb_symmetric_antenna_radiation_pattern_7ghz.png?direct&600 |}}
  
uwb/evb.1628339178.txt.gz · Last modified: 2021/08/07 12:26 by neilhao