lab3_2017.pdf - ECE145a 218A lab project#3 Reactively Tuned...

This preview shows page 1 - 3 out of 5 pages.

1 ECE145a / 218A lab project #3 Reactively Tuned Amplifier . Mark Rodwell, Thursday, September 28, 2017 Assignment Your assignment is to design and construct a reactively tuned amplifier. The transistor is to be an MRF 901 Bipolar Transistor. Please bias this at 10mA collector current and at a VCEof 5 volts. The goal is to obtain the maximum feasible gain at a signal frequency of 1.5 GHz or higher (145a) or 2.0 GHz or higher (218A) , while maintaining S11 and S22 below -10 dB. For 218A we add the additional real-world design requirement that the circuit must be unconditionally stable at allfrequenciesfrom DC to 5 GHz (~the highest frequency at which we can reliably measure). With the only restriction that you must not apply DC to the test ports of the network analyzer, you may design this amplifier in any way you desire. The following comments are simply suggestions. Network analyzers, sampling oscilloscopes, and spectrum analyzers all cost well above $20k, and all have easily-damaged Schottky-diode mixer/sampler inputs. To project these, you *must* use the input and output DC blocking capacitors, with a maximum value of 100 pF for each. Recall the safety considerations discussed earlier: do not use lead-based solder or solder-suckers. Use eye protection when cutting wires. Use normal electrical safety precautions: no bare feet, no liquids nearby, and do not touch bare conductors on circuits when biased, even if low-voltage. Figure 1: Bipolar transistor bias circuit.
2 Procedure Your work on this project should build on the test structure you earlier made in lab project 1b. For your reference, the bias circuit is repeated in Figure 1, and the details of physical construction in Figure 2, both shown below. In lab 1b, you had measured the transistor S-parameters. If these turned out to differ greatly from the data sheet values,

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture