Radio Frequency
Title: Directional Coupler
Objective:
To comprehend the propose and operational principle of the coupler by using the ED-3300D (Directional Coupler) module.
Equipment: No | Module Name | Item Name | Quantities | 1 | ED-4770 | Combo Tester | 1 | 2 | ED-3300A | VCO | 1 | 3 | ED-3300B | Detector | 1 | 4 | ED-3300C | Circulator | 1 | 5 | ED-3300D | Directional Coupler | 1 | 6 | Spectrum Analyzer | 5CE006 | 1 | 7 | Accessory | Banana-Banana | 2 | 8 | Accessory | 50Q Load | 2 | 9 | Accessory | BNC-Banana | 1 |
Procedures: 1. The circuit is connected as shown in Figure 1.
Figure 1 2. In order to supply the operational power to the ED-3300A (VCO) module, the voltages of channel 1 and channel 2 are adjusted to 1V and 12V respectively. 3. The output of the circulator, which is the input to the Port 1 of the Directional Coupler from 1.4GHz to 2.0GHz is measured and recorded in Table 1. 4. The Directional Coupler circuit is connected as shown in Figure 2.
Figure 2: Directional Coupler 5. The output from Port 2, Port 3 and Port 4 are measured respectively. In order to measure the output from a port, the other two ports must be matched with 50Ω resistor. 6. The output from Port 2, Port 3 and Port 4 are recorded in Table 2. 7. Then, the coupling coefficient, transmission coefficient, isolation coefficient and directivity of the directional coupler are calculated and recorded in Table 3.
Results: Frequency, GHz | 1.4 | 1.5 | 1.6 | 1.7 | 1.8 | 1.9 | 2.0 | Voltage, Vtune | 1.4 | 2.3 | 3.6 | 4.9 | 6.1 | 7.4 | 8.4 | P1 (Input Power), dBm | 0.48 | 5.63 | 6.55 | 6.00 | 5.80 | 5.47 | 5.97 |
Table 1: Input power to directional coupler
Frequency [GHz] | P2 | P3 | P4 | | Output Voltage [mV] | Output Power [dBm] | Output Voltage [mV] | Output Power [dBm] | Output Voltage [mV] | Output Power [dBm] | 1.4 | 187.32 | 0.35 | 36.02 | -12.63 | 2.47 | -28.94 | 1.5 | 483.79 | 6.84 | 113.96 | -4.40 | 25.63 | -18.22
Objective:
To comprehend the propose and operational principle of the coupler by using the ED-3300D (Directional Coupler) module.
Equipment: No | Module Name | Item Name | Quantities | 1 | ED-4770 | Combo Tester | 1 | 2 | ED-3300A | VCO | 1 | 3 | ED-3300B | Detector | 1 | 4 | ED-3300C | Circulator | 1 | 5 | ED-3300D | Directional Coupler | 1 | 6 | Spectrum Analyzer | 5CE006 | 1 | 7 | Accessory | Banana-Banana | 2 | 8 | Accessory | 50Q Load | 2 | 9 | Accessory | BNC-Banana | 1 |
Procedures: 1. The circuit is connected as shown in Figure 1.
Figure 1 2. In order to supply the operational power to the ED-3300A (VCO) module, the voltages of channel 1 and channel 2 are adjusted to 1V and 12V respectively. 3. The output of the circulator, which is the input to the Port 1 of the Directional Coupler from 1.4GHz to 2.0GHz is measured and recorded in Table 1. 4. The Directional Coupler circuit is connected as shown in Figure 2.
Figure 2: Directional Coupler 5. The output from Port 2, Port 3 and Port 4 are measured respectively. In order to measure the output from a port, the other two ports must be matched with 50Ω resistor. 6. The output from Port 2, Port 3 and Port 4 are recorded in Table 2. 7. Then, the coupling coefficient, transmission coefficient, isolation coefficient and directivity of the directional coupler are calculated and recorded in Table 3.
Results: Frequency, GHz | 1.4 | 1.5 | 1.6 | 1.7 | 1.8 | 1.9 | 2.0 | Voltage, Vtune | 1.4 | 2.3 | 3.6 | 4.9 | 6.1 | 7.4 | 8.4 | P1 (Input Power), dBm | 0.48 | 5.63 | 6.55 | 6.00 | 5.80 | 5.47 | 5.97 |
Table 1: Input power to directional coupler
Frequency [GHz] | P2 | P3 | P4 | | Output Voltage [mV] | Output Power [dBm] | Output Voltage [mV] | Output Power [dBm] | Output Voltage [mV] | Output Power [dBm] | 1.4 | 187.32 | 0.35 | 36.02 | -12.63 | 2.47 | -28.94 | 1.5 | 483.79 | 6.84 | 113.96 | -4.40 | 25.63 | -18.22