MINISTRY OF EDUCATION AND SCIENCE OF RUSSIA
SAINT PETERSBURG STATE ELECTROTECHNICAL UNIVERSITY
«LETI» N.A. V.I. ULYANOVA (LENINA)
Department of microwave electronics
9+0.5а=9.5 балл. Солидно!
REPORT
on individual homework №3
in the discipline «Microwave electronics»
Topic: Semiconductor devices
Student gr. 0207 _________________ Malikov B.I.
Teacher _________________ Ivanov V.A.
Saint Petersburg
2023
CONTENT
Task №1 …………………………………………………………………………... 3
Task №2 …………………………………………………………………………. 21
Task №3 …………………………………………………………………………. 32
List of used literature ……………………………………………………………. 61
Task №1
Diodes with positive dynamic resistance.
Calculate the current sensitivity of the DD with the coefficient of ideality
.What will be the increment of current when applying microwave power to the diode
Estimate the tangential sensitivity (expressed in
),
if the effective noise temperature of the diode is
,
and the amplifier band
.Describe the main similarities and differences in the functional role, structure, parameters of microwave devices with numbers:
1 and 3 for students with numbers Nstudent <= 5,
1 and 2 for students with numbers 6 <= Nstudent <=10,
1 and 4 for students with numbers 11 <= Nstudent <=15,
3 and 4 for students with numbers 16 <= Nstudent <=20.
3 and 2 for students with numbers Nstudent >= 21.
1.5. Describe the circuit models (not the application schemes!) microwave diodes with positive dynamic resistance (arbitrary choice), using available information sources Internet, lectures, AWR Microwave Office program, etc.
Given:
n = 1,85
Pmicro = 0,15 mW
Teff = 313 K
= 6 MHz
Solving:
1. Calculate the current sensitivity of the detector diode
The current
sensitivity of the detector diode is calculated using the following
formula, given that there is a limit on the maximum current
sensitivity for detector diodes
(
= 20 V-1)
[1]:
=
=
=
(1)
Hence, using the formula (1), we calculate the current sensitivity of the detector diode:
=
=
=
10,81 V-1
2. Calculate the increment of current when applying a microwave power of 0,15 mW to the diode
Let's write down an expression for the current sensitivity, given that the value of the current sensitivity is equal to the ratio of the rectified current increment to the value of the supplied microwave power [1]:
=
(2)
Then,
from formula (2), we express the value of the current increment
:
=
(3)
By the formula (3) we calculate the increment of the current:
=
= 10,81
0,15
10-3
= 1,622 mA
3. Evaluation of the tangential sensitivity of the detector diode
The tangential sensitivity of the detector diode is calculated by the following formula [1]:
=
10lg
(4)
We take into account that Pmin – the minimum value of the noise power, which is calculated by the Nyquist formula [2]:
Pmin
= Pn
= <
>R
= 4kTeff
(5)
where k = 1,38 10-23 J/K – Boltzmann constant.
From here, using the formula (5), we calculate the value of the noise power:
Pmin = Pn = < >R = 4kTeff = 4 1,38 10-23 313 6 106 = 1,037 10-13 W
Thus, the tangential sensitivity of the detector diode according to the formula (4) will be equal to:
= 10lg
=
10lg
=
99,84
dBm
4. The main similarities and differences in the functional role, structure, and parameters of microwave devices numbered 1 (detector diode) and 2 (pin diode)
4.1 Detector diode
4.1.1 The functional role of the detector diode
The main functional role of the detector diode is the conversion of weak microwave signals (order 102 106 W) in direct current or isolation (detection) of the low-frequency envelope of the signal. That is, the detector diode performs the function of an AC rectifier operating in the microwave range. At the same time, during detection, the rectifying property of the diode is used to isolate a lower frequency signal from amplitude-modulated microwave oscillations [3].