Microprocessor controlled RF modulator apparatus
The microprocessor-controlled RF modulator apparatus will provide repeatable, controlled scintillation on a test bench generated low-power RF target waveforms for the purpose of providing a target returns with realistic radar cross section characteristics during testing of the F-16 (or any other) fire control radar. The microprocessor-controlled RF modulator apparatus is utilized in line between an RF target signal generator and the target horn to provide a variety of target situations for testing radar hardware and software.
Latest The United States of America as represented by the Secretary of the Air Force Patents:
The present invention relates broadly to an RF modulator apparatus, and in particular to a microprocessor-controlled RF modulator apparatus.
The state of the art of radar target signal simulators is well represented and alleviated to some degree by the prior arts apparatus and approaches which are contained in the following U.S. Patents:
U.S. Pat. No. 3,571,479 issued to Horattas et al on Mar. 16, 1971;
U.S. Pat. No. 3,783,172 issued to Bernstein on Jan. 1, 1974;
U.S. Pat. No. 3,792,475 issued to Smetana on Mar. 9, 1972;
U.S. Pat. No. 4,168,502 issued to Susie on Mar. 15, 1978;
U.S. Pat. No. 4,224,583 issued to Larken on Nov. 29, 1978; and
U.S. Pat. No. 4,327,417 issued to Zaczek on June 6, 1980.
The early prior art approach to radar target generation or simulation is shown in the prior art patents of Horattas et al and Bernstein. The Horattas et al patent is directed toward a digital electronic target generator wherein digitized radar targets are stored in a memory matrix where range is "bit" oriented and aximuth is "word" oriented. Each word in the matrix represents an azimuth line segment of a target on a radar display and the bit position within a matrix word represents the target range, each bit being the smallest range unit defined by the resolution of the display. A computer identifies the location of all targets in the display matrix and transfers the data to parallel-to-serial shift registers which output serial pulse trains representative of the target words. An output signal having analog characteristics is produced by summing the shift register output results and may be used in a simulator visual display.
The Berstein patent comprises a radar simulator apparatus which utilizes a general-purpose digital computer and a special interface which generates suitable video signals in response to the computer outputs to drive a radar set. In a radar simulator in which several different types of radar targets are simulated, the apparatus of this invention is used to generate the video signals which will display a plurality of mobile targets on the radar set. A limited number of such targets are displayed, and the characteristics of these targets are entered into the computer. Information representing the initial locations of the selected targets and their directions and speeds of movement is inserted into the computer from a remote station, and the computer performs the necessary navigational computations to continually determine the location of the radar set in the gaming area, the bearing of each of the targets from the radar set, and the bearing of the radar antenna at any time. The ranges of all of the targets on a particular bearing are entered by the computer into a register in the order of increasing range from the radar set. When the simulated radar antenna bearing agrees with the target bearing, the stored target ranges are read from the register and are converted into video signals to drive the radar set.
The Smetana, Zaczek and Susie patents respectively illustrate the present day approach of prior art target signal simulators which have been either extremely complicated in that they were controlled by a digital computer or limited to producing signals useful in testing short range or low PRF radar systems. The computer based systems were complicated due to the extensive programming which is required to generate the delays that correspond to the range of the simulated target and to calculate the pulse repetition frequency of the simulated target signal. The limited range of the simulators which did not use digital computers, resulted primarily from the fact that they provided no convenient means for generating a simulated target signal in which the time interval between adjacent pulses of the signal was less than the transit time to and from the simulated target.
The Larkin patent presents another novel approach to the field of radar target signal simulation through the use of a linear attenuator which uses a dc control current to change the RF resistance of PIN diodes that are in series and parallel with the load. As the control current changes, the RF resistance of the series diode will vary inversely, while the RF resistance of the parallel diode will vary directly thereby providing attenuation which changes linearly as a function of the control current through the series diode. The present invention is directed to a microprocessor-controlled RF modulator apparatus which provides RF target return signals to a fire control radar with realistic radar characteristics.
SUMMARY OF THE INVENTIONThe present invention utilizes a microprocessor which is controllable in both attenuation range and frequency to amplitude modulate a test bench generated radar target return signal. The radar characteristic of the target are varied with respect to aspect angle, radar cross section and other physical parameter to provide a non-stable, time/amplitude varying signal which is representative of a true radar target.
It is one object of the present invention, therefore, to provide an improved microprocessor-controlled RF modulator apparatus.
It is another object of the invention to provide an improved microprocessor-controlled RF modulator apparatus that will generate repeatable, controlled scintillation to low-power waveforms.
It is another object of the invention to provide an improved microprocessor-controlled RF modulator apparatus with a realistic target simulation since the received target signal is amplitude modulated by the microprocessor unit.
It is another object of the invention to provide an improved microprocessor-controlled RF modulator apparatus which is controllable in both attenuation range and frequency.
It is another object of the invention to provide an improved microprocessor-controlled RF modulator apparatus wherein the degree of modulation can be controlled within minimum and maximum levels.
It is another object of the invention to provide an improved microprocessor-controlled RF modulator apparatus that generates a non-stable varying target return signal which is representative of a true air-to-air target.
These and other advantages, objects and features of the invention will become more apparent after considering the following description taken in conjunction with the illustrative embodiment in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a block diagram illustrating the use of the microprocessor-controlled RF modulator apparatus in a standard test set-up,
FIG. 2 is a block diagram of the microprocessor-controlled RF modulator apparatus according to the present invention,
FIG. 3 is a graphical representation of a variety of sample modulation waveforms,
FIG. 4 is a schematic diagram of the Z-80 central processor unit,
FIG. 5 is a schematic diagram of the 20K EPROM, memory unit,
FIG. 6 is a schematic diagram of the output latch unit and the digital to analog converter (DAC) unit, and,
FIG. 7 is a schematic diagram of the PIN diode attenuator unit.
DESCRIPTION OF THE PREFERRED EMBODIMENTTurning now to FIG. 1 there is shown a block diagram of a standard test set-up utilizing the microprocessor-controlled RF modulator apparatus 10 for testing a fire control radar unit 12. The system test bench unit 14 typically comprises an RF target generator unit 14a, a target controller unit 14b and an avionics simulator panel unit 14c. The test bench generated target signal is applied to the microprocessor-controlled RF modulator apparatus 10 wherein it is amplitude modulated and is controlled in both frequency and attenuation range. The modulated RF target return signal from the microprocessor-controlled RF modulator apparatus 10 is applied to the target horn 16. The target horn 16 is arranged to transmit the modulated RF target return signal to the fire control radar unit 12 which is under test.
The microprocessor-controlled RF modulator apparatus will provide repeatable, controlled scintillation to low-power RF waveforms for the purpose of testing the F-16 or any other fire control radar. The microprocessor-controlled RF modulator apparatus 10 is shown in FIG. 1 as installed in line between an RF target generator unit 14a and a target horn unit 16 to provide many added capabilities for testing the hardware and software of a fire control radar unit. This apparatus provides the user with a most realistic target simulation since the received target signal is amplitude modulated by the Z-80 microprocessor (which is shown in FIG. 2) and is controllable in both attenuation range and frequency. The scintillation (modulation) that can be provided can be square wave, swept square wave, triangle wave, sine wave or repeatable random noise at a number of frequencies and, in the case of the square wave functions, at a number of duty factors. The type of modulation, the frequency of the modulation and the duty factor are selected by setting the mini-lever switches which are respectively labelled Mode, Port 1 and Port 2 on the front panel of the microprocessor-controlled RF modulator apparatus. An operator may also control the degree of modulation by selecting the desired attenuation level with the Attenuation knob on the front panel. The minimum and maximum attenuation levels comprise a range of 0 to 60 db in steps of 0, 3, 10, 20, or 60 db.
A most effective use of the microprocessor-controlled RF modulator apparatus here at the Westinghouse Defense Center is to provide this controlled scintillation to a target signal that is generated by the F-16 system test bench. Now, instead of having the AN/APG-66 Fire Control Radar search, acquire and track a non-varying, non-oscillating, artificial target, the F-16 radar unit which is under test, must now respond to a simulated target signal whose generated aspect angle, radar cross section and physical characteristics are changing in a most realistic way. The amplitude modulation or scintillation, that is applied to the F-16 system test bench-generated RF target signal, provides a non-stable, varying RF target signal return which is a better representation of a true air-to-air target.
The versatility of the microprocessor-controlled modulator apparatus is especially evident in jamming scenarios since the radar no longer has a steady and solid target to detect and track, but instead, has to detect a target signal that is oscillating or modulating in the presence of a threat environment. This type of testing is valuable since, with the use of the microprocessor-controlled RF modulator apparatus, realistic target returns can be processed in the radar in both ECM and non-ECM environments.
Turning now to FIG. 2 there is shown a block diagram of the microprocessor-controlled RF modulator apparatus. Input ports unit 20 is operatively connected to the data select means which is not shown in FIG. 2 but is shown in FIG. 1 as the minilever switches that are labelled, Mode, Port 1 and Port 2. The input ports unit 20 which is connected to the Z-80 microprocessor unit 22 communicates the switch settings that control the output waveform parameters to the Z-80 central processor unit (CPU) 22. The Z-80 CPU unit 22 receives a 4 MHz clock signal from clock unit 26. An EPROM memory unit 24 which is a 20K memory unit is operatively connected to the Z-80 CPU unit 22. The EPROM memory unit 24 stores the waveform data and parameters which are utilized by the Z-80 CPU unit 22 to generate the simulated radar target test signal. The digital data which represents the radar target test signal is applied through output latch unit 28 to the digital to analog (DAC) unit 30 for conversion to an analog signal. The analog signal from the DAC unit 30 is applied to the amplitude control unit 32 which in response thereto generates a control voltage signal. The pin diode attenuator unit 34 utilizes the control voltage signal to modulate and structure the RF in signal into the selected waveform shape which becomes the RF out signal.
The microprocessor-controlled RF modulator apparatus utilizes the Z-80 CPU and its associated hardware and software to control the RF input signal that is received by the PIN diode unit. The PIN diode unit comprises a General Microwave D1958 PIN diode attenuator unit that provides a linear correspondence between a control voltage (0-6 VDC) and attenuation (0-60 dB). This control voltage which is converted to an analog signal by the digital analog converter unit and the amplitude control unit is the product of the microprocessor outputs and/or stored PROM memory data. Typical control voltage waveforms which may be generated by the microprocessor-controlled modulator apparatus are shown in FIG. 3 and are labelled (a) through (h). In Table I below there is shown the switch positions which provide the logic code to the Z-80 CPU to generate the digital signal that represents a particular output waveform.
TABLE I
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The switch logic positions for the microprocessor-
controlled RF modulator apparatus is shown as follows:
Mode Port 1 Port 2 Result
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0 X X Not used
1 X X 0 dB Attenuation
2 0 X RANDOM DATA - 125 Hz Switching
Freq.
1 X RANDOM DATA - 80 Hz
2 X RANDOM DATA - 45 Hz
3 X RANDOM DATA - 20 Hz
4 X RANDOM DATA - 15 Hz
5 X RANDOM DATA - 2 Hz
6 X RANDOM DATA - 1 Hz
7 X RANDOM DATA - .5 Hz
3 0 X 6 Hz SQUARE
1 X 35 Hz SQUARE
2 X 80 Hz SQUARE
3 X 150 Hz SQUARE
4 X 180 Hz SQUARE
5 X 250 Hz SQUARE
6 X 350 Hz SQUARE
7 X 650 Hz SQUARE
X 0 97.5% Duty SQUARE
X 1 88.0% Duty SQUARE
X 2 73.0% Duty SQUARE
X 3 50.0% Duty SQUARE
X 4 27.0% Duty SQUARE
X 5 12.0% Duty SQUARE
X 6 2.5% Duty SQUARE
4 X X 28.6-80 Hz SWEPT SQUARE
in 2 seconds
5 0 X .5 Hz SINE
1 X 2 Hz SINE
2 X 12 Hz SINE
3 X 24 Hz SINE
4 X 28 Hz SINE
5 X 55 Hz SINE
6 X 110 Hz SINE
7 X 220 Hz SINE
6 0 X 2 Hz TRIANGLE
1 X 10 Hz TRIANGLE
2 X 20 Hz TRIANGLE
3 X 40 Hz TRIANGLE
4 X 50 Hz TRIANGLE
5 X 83 Hz TRIANGLE
6 X 125 Hz TRIANGLE
7 X 167 Hz TRIANGLE
7 X X Not used
______________________________________
(Note: X indicates that the switch position doesn't matter.)
The microprocessor is an eight-bit, 40-pin device, which is operated by a 4 MHz clock and uses 20K of programmed data that is stored on ten (10) 2K EPROM memory chips. The remainder of the circuitry of the microprocessor-controlled RF modulator apparatus controls the buffering of the address and data lines, the I/O circuitry, and provides the gain and impedence matching which is required to drive the PIN diode attenuator.
In FIGS. 4 through 7, there is shown a complete schematic diagram of the microprocessor-controlled RF modulator apparatus wherein similarly designated points are commonly connected. The parts list for the schematic diagram of FIGS. 4 through 7 is given in Table 2 as follows:
TABLE 2
______________________________________
1 - Z-80 Microprocessor (Zilog)
1 - 7406 MED
1 - 74145 MED
6 - 74244 MED
2 - 74243 MED
1 - 4 MHz oscillator
10 - 2716 EPROMs Intel Corp.,
1 - 74100 MED
1 - DAC
1 - PIN Diode Attenuator (Gen. Microwave D1958)
3 - Minilever Switches
1 - 7400 MED
1 - 3P2T switch
1 - 2PlT momentary switch
2 - 741 Op-amp MED
1 - 5P wafer switch
2 - 0-20K trim pots
2 - 10K, 1/8 W resistor
1 - 400 ohm, 1/8 W resistor
1 - 22 ohm, 1/8 W resistor
1 - 82 ohm, 1/8 W resistor
1 - 220 ohm, 1/8 W resistor
23 - 330 ohm, 1/8 W resistor
______________________________________
In FIG. 4 there is shown a schematic diagram of the Z-80 microprocessor (CPU) and its associated circuitry. The elements of FIG. 4 can be related to the block diagram of FIG. 2 as follows. The Z-80 CPU of FIG. 2 comprises Z-80 microprocessor unit, the data line buffer units (74243); the address line buffer units (74244); the demultiplexer unit (74145) and its associated resistor array. In FIG. 5 there is shown the 20K EPROM memory unit which comprises ten 2K EPROM units (2716). In FIG. 6 there is shown the input ports unit of FIG. 2 which comprises the three minilever switches (Mode Sel, Port 1 and Port 2), the address line buffer units (74244) and the NAND gates (7400) which are associated with the buffer units. In FIG. 6 there is also shown the output latch unit of FIG. 2 which comprises the output latch unit (74100), the digital to analog converter unit (DAC) and the PIN diode attenuator. In FIG. 7 there is shown the amplitude control unit of FIG. 2 which comprises a pair of operational amplifier units (741) and its associated circuitry that includes a five position wafer switch as shown.
A desirable feature of the present apparatus is its programmability. The entire operation of the microprocessor-controlled RF modulator apparatus can be modified by changing the program of the EPROMs. The hardware does not need to be modified at all. The microprocessor-controlled RF modulator apparatus is rack-mountable and uses +5 V, +15 V and -15 V DC power.
The program memory is mapped as follows:
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0000H-07FFH (2K) Program Executive
0800H-08FFH (1K) Sine Wave Simulation
0C00H-OFFFH (1K) Unused
1000H-4FFFH (16K) Random Noise Simulation
______________________________________
TABLE 3
__________________________________________________________________________
ER LINE
ADDR
B1 B2 B3 B4 Z80 ASSEMBLER I.L.S.O.
__________________________________________________________________________
1 ;*
2 ; MICROPROCESSOR CONTROLLED RF ATTENUATOR
3 0000
00 NOP
4 0001
00 NOP
5 0002
00 NOP
6 0003
00 NOP
7 0004
00 NOP
8 0005
00 NOP
9 0006
00 NOP
10 0007
00 NOP
11 0008
00 NOP
12 0009
00 NOP
13 000A
DB 01 START IN A,(1)
14 000C
3D DEC A
15 000D
CA 34 00 JP Z,0DB
16 0010
3D DEC A
17 0011
CA F7 01 JP Z,SAMPLE
18 0014
3D DEC A
19 0015
CA 1C 01 JP A,SQW
20 0018
3D DEC A
21 0019
CA 83 00 JP Z,SWP
22 001C
3D DEC A
23 001D
CA 3B 00 JP Z,SINE
24 0020
3D DEC A
25 0021
CA EE 00 JP Z,TRW
26 0024
D3 02 RNDM IN A,(2)
27 0026
DD 21 67 01 LD IX,TBL2
28 002A
21 FF 3F LD HL,3FFFH
29 002D
FD 21 00 10 LD IY,1000H
30 0031
C3 48 00 JP S0
31 0034
3E 00 ODB LD A,O
32 0036
D3 10 OUT (10H),A
33 0038
C3 0A 00 JP START
34 003B
DB 02 SINE IN A,(2)
35 003D
DD 21 5F 01 LD IX,TBL1
36 0041
21 FF 03 LD HL,03FFH
37 0044
FD 21 00 0B LD IY,0900H
38 0048
16 00 GO LD D,O
39 004A
5F LD E,A
40 004B
DD 19 ADD IX,DE
41 004D
01 01 00 LD BC,1
42 0050
D6 04 SUB 4
43 0052
FA 50 00 SKIP JP M,CEXT
44 0055
DD 7E 00 LD A, IX)
45 0058
4F LD C,A1
46 0059
C3 66 00 JP OUT
47 0050
DD 7E 00 NEXT LD A,(IX)
48 005F
3D LOOP DEC A
49 0060
CA 66 00 JP Z,OUT
50 0063
C3 5F 00 JP LOOP
51 0066
FD 7E 00 OUT LD A,(IY + 0)
52 0069
D3 10 OUT (10H),A
53 0068
FD 09 ADD IY,BO
54 0060
ED 42 SHC HL,BC
55 006F
FA 79 00 JP M,CHJZ
56 0072
DB 02 IN A,(2)
57 0074
D6 04 SUB 4
58 0076
C3 52 00 JP SKIP
59 0079
DB 01 CHUZ IN A,(1)
60 0078
D6 05 SUB 5
61 0070
CA 3B 00 JP Z,SINE
62 0080
C3 24 00 JP RNDM
63 0083
01 00 00 SWP LD BC,O
64 0086
3E FF SWL2 LD A,OFFH
65 0088
D3 10 OUT (10H),A
66 008A
11 FF FF LD DE,-1
67 008D
21 20 04 LD HL,105BD
68 0090
09 ADD HL,BC
69 0091
19 SWL ADD HL,DE
70 0092
38 FD JP C,SWL
71 0094
00 NOP
72 0095
00 NOP
73 0096
00 NOP
74 0097
00 NOP
75 0098
00 NOP
76 0099
00 NOP
77 009A
00 NOP
78 009B
00 NOP
79 009C
00 NOP
80 009D
00 NOP
81 009E
00 NOP
82 009F
00 NOP
83 00A0
00 NOP
84 00A1
00 NOP
85 00A2
00 NOP
86 00A3
00 NOP
87 00A4
00 NOP
88 00A5
00 NOP
89 00A6
00 NOP
90 00A7
00 NOP
91 00A8
00 NOP
92 00A9
00 NOP
93 00AA
00 NOP
94 00AB
00 NOP
95 00AC
00 NOP
96 00AD
00 NOP
97 00AE
00 NOP
98 00AF
00 NOP
99 00B0
00 NOP
100 00B1
00 NOP
101 00B2
00 NOP
102 00B3
00 NOP
103 00B4
00 NOP
104 00B5
00 NOP
105 00B6
00 NOP
106 00B7
00 NOP
107 00B8
00 NOP
108 00B9
00 NOP
109 00BA
00 NOP
110 00BB
00 NOP
111 00BC
00 NOP
112 00BD
00 NOP
113 00BE
00 NOP
114 00BF
00 NOP
115 00C0
3E 00 LD A,
116 00C2
D3 10 OUT (10H),A
117 00C4
11 FF FF LD DE,-1
118 00C7
21 20 04 LD HL,1056D
119 00CA
09 ADD HL,BC
120 00CB
19 SWL1 ADD HL,DE
121 00CC
38 FD JR C,SWL1
122 00CE
0B DEC BC
123 00CF
0B DEC BC
124 00D0
0B DEC BC
125 00D1
0B DEC BC
126 00D2
0B DEC BC
127 00D3
0B DEC BC
128 00D4
0B DEC BC
129 00D5
0B DEC BC
130 00D6
0B DEC BC
131 00D7
0B DEC BC
132 00D8
0B DEC BC
133 00D9
0B DEC BC
134 00DA
0B DEC BC
135 00DB
0B DEC BC
136 00DC
0B DEC BC
137 00DD
0B DEC BC
138 00DE
0B DEC BC
139 00DF
0B DEC BC
140 00E0
0B DEC BC
141 00E1
0B DEC BC
142 00E2
0B DEC BC
143 00E3
0B DEC BC
144 00E4
0B DEC BC
145 00E5
0B DEC BC
146 00E6
0B DEC BC
147 00E7
0B DEC BC
148 00E8
78 LD A,3
149 00E9
E6 07 AND 07
150 00EB
47 LD B,A
151 00EC
18 98 JP SWL2
152 00EE
DB 02 TRW IN A,(2)
153 00F0
57 LD D,A
154 00F1
06 00 LD B,O
155 00F3
4F LD C,A
156 00F4
DD 21 6F 01 LD IX,TBL3
157 00F8
DD 09 ADD IX,BC
158 00FA
DD 46 00 LD B,(IX + 0)
159 00FD
DB 02 TL4 IN A,(2)
160 00FF
BA CP D
161 0100
20 EC JR NZ,TRW
162 0102
3E 00 LD A,0
163 0104
D3 10 TL3 OUT (10H),A
164 0106
3C INC A
165 0107
28 06 JR Z,TL1
166 0109
48 LD C,B
167 010A
0D TL2 DEC C
168 010B
20 FD JR NZ,TL2
169 010D
18 F5 JR TL3
170 010F
3E FF TL1 LD A,OFFH
171 0111
D3 10 TL6 OUT (10H),A
172 0113
3D DEC A
173 0114
28 E7 JR Z,TL4
174 0116
48 LD C,B
175 0117
OD TLS DEC C
176 0118
20 FD JR NZ,TL5
177 011A
18 F5 JR TL6
178 011C
DB 04 SQW IN A,(4)
179 011E
E6 07 AND 007H
180 0120
4F LD C,A
181 0121
DB 02 IN A,(2)
182 0123
E6 07 AND 007H
183 0125
CB 27 SLA A
184 0127
CB 27 SLA A
185 0129
CB 27 SLA A
186 012B
81 ADD A,C
187 0120
CB 27 SLA A
188 012E
06 00 LD B,O
189 0130
4F LD C,A
190 0131
DD 21 77 01 LD IX,TBL4
191 0135
DD 09 ADD IX,BC
192 0137
DD 56 00 LD D,(IX + 0)
193 013A
DD 5E 01 LD E,(IX + 1)
194 013D
DB 02 IN A,(2)
195 013F
47 LD B,A
196 0140
3E 00 SL5 LD A,O
197 0142
D3 10 OUT (10H),A
198 0144
7A LD A,D
199 0145
4A SL2 LD C,D
200 0146
OD SL1 DEC C
201 0147
20 FD JR NZ,SL1
202 0149
3D DEC A
203 014A
20 F9 JR NZ,SL2
204 014C
DB 02 IN A,(2)
205 014E
B8 CP B
206 014F
20 CB JR NZ,SQW
207 0151
3E FF LD A,OFFH
208 0153
D3 10 OUT (10H),A
209 0155
7B LD A,E
210 0156
4B SL4 LD C,E
211 0157
0D SL3 DEC C
212 0158
20 FD JR NZ,SL3
213 015A
3D DEC A
214 015B
20 F9 JR NZ,SL4
215 015D
18 E1 JR SL5
216 015F
FF TRL1 DEFB OFFH
217 0160
4C DEFB 04CH
218 0161
09 DEFB 9H
219 0162
02 DEFB 2H
220 0163
01 DEFB 1
221 0164
02 DEFB 2
222 0165
04 DEFB 4
223 0166
08 DEFB 8
224 0167
08 TBL2 DEFB 8
225 0168
04 DEFB 4
226 0169
02 DEFB 2
227 016A
01 DEFB 1
228 016B
01 DEFB 1
229 016C
02 DEFB 2
230 016D
04 DEFB 4
231 016E
08 DEFB 3
232 016F
00 TBL3 DEFB 0
233 0170
2E DEFB 46D
234 0171
16 DEFB 22D
235 0172
0E DEFB 14D
236 0173
08 DEFB 3D
237 0174
04 DEFB 4D
238 0175
02 DEFB 2D
239 0176
01 DEFB 1D
240 0177
21 TBL4 DEFB 33D
241 0178
E1 DEFB 225D
242 0179
41 DEFB 65D
243 017A
C1 DEFB 193D
244 017B
61 DEFB 97D
245 017C
A1 DEFB 1610
246 017D
B1 DEFB 129D
247 017E
B1 DEFB 129D
248 017F
A1 DEFB 161D
249 0180
61 DEFB 97D
250 0181
C1 DEFB 193D
251 0182
41 DEFB 65D
252 0183
E0 DEFB 224D
253 0184
20 DEFB 32D
254 0185
00 DEFB 0D
255 0186
01 DEFB 1D
256 0187
0E DEFB 14D
257 0188
62 DEFB 98D
258 0189
1C DEFB 28D
259 018A
54 DEFB 84D
260 018B
2A DEFB 42D
261 018C
46 DEFB 70D
262 018D
38 DEFB 56D
263 018E
38 DEFB 56D
264 018F
46 DEFB 70D
265 0190
2A DEFB 42D
266 0191
54 DEFB 84D
267 0192
1C DEFB 28D
268 0193
62 DEFB 98D
269 0194
0E DEFB 14D
270 0195
70 DEFB 112D
271 0196
01 DEFB 1D
272 0197
09 DEFB 9D
273 0198
3E DEFB 62D
274 0199
12 DEFB 18D
275 019A
35 DEFB 53D
276 019B
1B DEFB 27D
277 019C
2C DEFB 44D
278 019D
24 DEFB 36D
279 019E
24 DEFB 36D
280 019F
2C DEFB 44D
281 01A0
1B DEFB 27D
282 01A1
35 DEFB 53D
283 01A2
12 DEFB 18D
284 01A3
3E DEFB 62D
285 01A4
09 DEFB 9D
286 01A5
47 DEFB 71D
287 01A6
01 DEFB 1D
288 01A7
07 DEFB 7D
289 01A8
2E DEFB 46D
290 01A9
0E DEFB 14D
291 01AA
28 DEFB 40D
292 01AB
14 DEFB 20D
293 01AC
21 DEFB 33D
294 01AD
18 DEFB 27D
295 01AE
18 DEFB 27D
296 01AF
20 DEFB 32D
297 01B0
14 DEFB 20D
298 01B1
28 DEFB 40D
299 01B2
0E DEFB 14D
300 01B3
2E DEFB 46D
301 01B4
07 DEFB 7D
302 01B5
35 DEFB 53D
303 01B6
01 DEFB 1D
304 01B7
07 DEFB 7D
305 01B8
2C DEFB 44D
306 01B9
0D DEFB 13
307 01BA
25 DEFB 37
308 01BB
13 DEFB 19D
309 01BC
1F DEFB 31D
310 01BD
19 DEFB 25D
311 01BE
19 DEFB 25D
312 01BF
1F DEFB 31D
313 01C0
13 DEFB 19D
314 01C1
35 DEFB 37D
315 01C2
0D DEFB 13D
316 01C3
2B DEFB 43D
317 01C4
07 DEFB 7D
318 01C5
32 DEFB 50D
319 01C6
01 DEFB 1D
320 01C7
06 DEFB 6D
321 01C8
24 DEFB 36D
322 01C9
0B DEFB 11D
323 01CA
1F DEFB 31D
324 01CB
10 DEFB 16D
325 01CC
1A DEFB 26D
326 01CD
15 DEFB 21D
327 01CE
15 DEFB 21D
328 01CF
1A DEFB 26D
329 01D0
10 DEFB 16D
330 01D1
1F DEFB 31D
331 01D2
DB DEFB 11D
332 01D3
24 DEFB 36D
333 01D4
06 DEFB 6D
334 01D5
29 DEFB 41D
335 01D6
01 DEFB 1D
336 01D7
05 DEFB 5D
337 01D8
1F DEFB 31D
338 01D9
09 DEFB 9D
339 01DA
1A DEFB 26D
340 01DB
0D DEFB 13D
341 01DC
16 DEFB 22D
342 01DD
12 DEFB 18D
343 01DE
12 DEFB 18D
344 01DF
16 DEFB 22D
345 01EO
0D DEFB 13D
346 01E1
1A DEFB 26D
347 01E2
09 DEFB 9D
348 01E3
1E DEFB 30D
349 01E4
05 DEFB 5D
350 01E5
23 DEFB 35D
351 01E6
01 DEFB 1D
352 01E7
04 DEFB 4D
353 01E3
16 DEFB 22D
354 01E9
07 DEFB 7D
355 01EA
13 DEFB 19D
356 01EB
0A DEFB 10D
357 01EC
10 DEFB 16D
358 01ED
0D DEFB 13D
359 01EE
0D DEFB 13D
360 01EF
10 DEFB 160
361 01F0
0A DEFB 10D
362 01F1
13 DEFB 19D
363 01F2
07 DEFB 7D
364 01F3
16 DEFB 22D
365 01F4
04 DEFB 4D
366 01F5
19 DEFB 25D
367 01F6
01 DEFB 1D
368 01F7
FD 21 00 10 SAMPLE LD IY,1000H
369 01F8
21 FF 3F LD HL,3FFFH
370 01FE
FD 46 00 LD B,(IY)
371 0201
DD 21 00 FF SCF LD IX,OFF00H
372 0205
FD 23 INC IY
373 0207
2B DEC HL
374 0208
31 00 00 LD SP,0
375 020B
ED 7A ADC HL,SP
376 020D
CA F7 01 JP Z,SAMPLE
377 0210
31 01 00 LD SP,1
378 0213
FD 7E 00 LD A,(IY)
433 0275
3D JJ DEC A
434 0276
C2 75 02 JP NZ,JJ
435 0279
DB 02 IN A,(2)
436 027B
3D DEC A
437 027C
3D DEC A
438 027D
3D DEC A
439 027E
3D DEC A
440 027F
3D DEC A
441 0280
CA BE 02 JP Z,NOUT
442 0283
3E FF LD A,FFH
443 0285
3D FF DEC A
444 0286
C2 85 02 JP NZ,FF
445 0289
3E FF LD A,OFFH
446 028B
3D KK DEC A
447 028C
C2 8B 02 JP NZ,KK
448 028F
3E 2C LD A,2CH
449 0291
3D LL DEC A
450 0292
C2 91 02 JP NZ,LL
451 0295
DB 02 IN A,(2)
452 0297
3D DEC A
453 0298
3D DEC A
454 0299
3D DEC A
455 029A
3D DEC A
456 029B
3D DEC A
457 029C
3D DEC A
458 029D
CA BE 02 JP Z,NOUT
459 02A0
3E FF LD A, FFH
460 02A2
3D GG DEC A
461 02A3
C2 A2 02 JP NZ IGG
462 02A6
3E FF LD A, FFH
463 02A8
3D HH DEC A
464 02A9
C2 AB 02 JP NZ HH
465 02AC
3E FF LD A,OFFH
466 02AE
3D NN DEC A
467 02AF
C2 AE 02 JP NZ,NN
468 02B2
3E FF LD A,OFFH
469 02B4
3D PP DEC A
470 02B5
C2 B4 02 JP NZ PP
471 02B8
3E 5E LD A, EH
472 02BA
3D QQ DEC A
473 02BB
C2 BA 02 JP NZ, QQ
474 02BE
78 NOUT LD A,B
475 02BF
D3 10 OUT (10H),A
476 02C1
DD 39 ADD IX,SP
477 02C3
DA 01 02 JP C,GOZ
478 02C6
C3 23 02 JP ADD
479 02C9
ED 44 NEG NEG
480 02CB
CB 20 SLA B
481 02CD
0E 00 LD C,O
482 02CF
5F LD E,A
483 02D0
78 ADDNEG LD A,E
484 02D1
81 ADD A,C
485 02D2
D2 D6 02 JP NC,NBYNEG
486 02D5
05 DEC B
487 02D6
4F NBYNEG LD C,A
488 02D7
00 NOP
489 02D8
D2 DC 02 JP NC,NCYNEG
490 02DB
05 DEC B
491 02DC
4F NCYNEG LD C,A
492 02DD
DB 02 LOOPNG IN A,(2)
493 02DF
3C INC A
494 02E0
3D DEC A
495 02E1
CA 6B 03 JP Z,NEGOUT
496 02E4
3E 03 LD A,3H
497 02E6
3D AAA DEC A
498 02E7
C2 E6 02 JP NZ,AAA
499 02EA
DB 02 IN A,(2)
500 02EC
3D DEC A
501 02ED
CA 68 03 JP A,NEGOUT
502 02F0
3E 08 LD A,BH
503 02F2
3D BBB DEC A
504 02F3
C2 F2 02 JP NZ,BBB
505 02F6
DB 02 IN A,(2)
506 02F8
3D DEC A
507 02F9
3D DEC A
508 02FA
CA 68 03 JP Z,NEGOUT
509 02FD
3E 14 LD A,14H
510 02FF
3D CCC DEC A
511 0300
C2 FF 02 JP NZ,CCC
512 0303
DB 02 IN A,(2)
513 0305
3D DEC A
514 0306
3D DEC A
515 0307
3D DEC A
516 0308
CA 6B 03 JP A,NEGOUT
517 030B
3E 2D LD A,2DH
518 030D
3D DDD DEC A
519 030E
C2 0D 0D JP NZ,DDD
520 0311
DB 02 IN A,(2)
521 0313
3D DEC A
522 0314
3D DEC A
523 0315
3D DEC A
524 0316
3D DEC A
525 0317
CA 6B 03 JP Z,NEGOUT
526 031A
3E FF LD A,OFFH
527 031C
3D EEE DEC A
528 031D
C2 1C 03 JP NZ,EEE
529 0320
3E CE LD A,OCEH
530 0322
3D JJJ DEC A
531 0323
C2 22 03 JP NZ,JJJ
532 0326
DB 02 IN A,(2)
533 0328
3D DEC A
534 0329
3D DEC A
535 032A
3D DEC A
536 032B
3D DEC A
537 032C
3D DEC A
538 032D
CA 6B 03 JP Z,NEGOUT
539 0330
3E FF LD A,OFFH
540 0332
3D FFF DEC A
541 0333
C2 32 03 JP NZ,FFF
542 0336
3E FF LD A,OFFH
543 0338
3D KKK DEC A
544 0339
C2 38 03 JP NZ,KKK
545 033C
3E 2C LD A,2CH
546 033E
3D LLL DEC A
547 033F
C2 3E 03 JP NZ,LLL
548 0342
DB 02 IN A,(2)
549 0344
3D DEC A
550 0345
3D DEC A
551 0346
3D DEC A
552 0347
3D DEC A
553 0348
3D DEC A
554 0349
3D DEC A
555 034A
CA 6B 03 JP A,NEGOUT
556 034D
3E FF LD A,OFFH
557 034F
3D GGG DEC A
558 0350
C2 4F 03 JP NZ,GGG
559 0353
3E FF LD A,OFFH
560 0355
3D HHH DEC A
561 0356
C2 55 03 JP NZ,HHH
562 0359
3E FF LD A,OFFH
563 035B
3D NNN DEC A
564 0350
C2 5B 03 JP NZ,NNN
565 035F
3E FF LD A,OFFH
566 0361
3D PPP DEC A
567 0362
C2 61 03 JP NZ,PPP
568 0365
3E 5E LD A,5EH
569 0367
3D QQQ DEC A
570 0368
C2 67 03 JP NZ,QQQ
571 036B
78 NEGOUT LD A,B
572 036C
D3 10 OUT (10H),A
573 036E
DD 39 ADD IX,SP
574 0370
DA 01 02 JP C,GOZ
575 0373
C3 D0 02 JP ADDNEG
576 0376 END
__________________________________________________________________________
ASSEMBLER ERRORS = 0
K/WESTINGHOUSE Z80 ASSEMBLER EC-02 VER. DATE 10/5/83 TIME OFF 15
CROSS REFERENCE
LABEL VALUE REFERENCE
__________________________________________________________________________
AA 0239 -400
AAA 02E6 -497
ADD 0223 -386
ADDNEG 0200 -483
BB 0245 -406
BBB 02F2 -503
CC 0252 -413
CCC 02FF -510
CHUZ 0079 -59
DD 0260 -421
DDD 030D -513
EE 026F -430
EEE 031C -527
FF 0285 -443
FFF 0332 -540
GG 02A2 -460
GGG 034F -557
GO 0048 -33
GOZ 0201 -371
H 02A8 -463
HHH 0355 -560
JJ 0275 -433
JJJ 0322 -530
KK 0288 -446
KKK 0338 -543
LL 0291 -449
LLL 033E -546
LOOP 005F -43
LOOPNG 02DD -492
LOOPZ 0230 -395
MEMORY M 0000 0
NBARRY 0229 -390
NBYNEG 02D6 -487
NCARRY 022F -394
NCYNEG 02DC -491
NEG 0209 -479
NEGOUT 036B -571
NEXT 005C -47
NN 02AE -466
NNN 035B -563
NOUT 02BE -474
ODB 0034 -31
OUT 0066 -51
POS 021E -383
PP 0284 -469
PPP 0361 -566
QQ 02BA -472
QQQ 0367 -569
RNDM 0024 -26
SAMPLE 01F7 -363
SINE 0038 -34
SKIP 0052 -43
SL1 0146 -200
SL2 0145 -199
SL3 0157 -211
SL4 0156 -210
SL5 0140 -196
SOW 011C - 178
STACK S 0000 0
START 000A -13
SWL 0091 -69
SWL1 00CB -120
SWL2 0086 -64
SWP 0083 -63
TBL1 015F -216
TBL2 0167 -224
TBL3 016F -232
TBL4 0177 -240
TL1 010F -170
TL2 010A -167
TL3 0104 -163
TL4 00FD -159
TL5 0117 -175
TL6 0111 -171
TRW 00EE -152
__________________________________________________________________________
Other important areas in which the microprocessor-controlled RF modulator apparatus may be used are in developing NCTR algorithms and sideband/sidelobe track processing. Any periodic waveform that can be represented by a series of points (typically 1K or 2K of discrete quanta levels) can be accessed, read and used to modulate a testbench-generated target return. Engine sideband data, NCTR (Non-conforming target recognition) data and any irregular X-band returns of any type can be simulated easily, using existing hardware, with all modifications reserved to the executive algorithm and/or tables of programmed software.
Although the invention has been described with reference to a particular embodiment, it will be understood to those skilled in the art that the invention is capable of a variety of alternative embodiments within the spirit and scope of the appended claims.
Claims
1. A microprocessor-controlled RF modulator apparatus for testing a fire control radar comprising in combination:
- means for processing digital data which is operated by a four MHz clock means, said processing means utilizing said digital data to generate a digital target return signal,
- memory means for storing a predetermined amount of digital data, said memory means being eraseable and programmable, said memory means being operatively connected to said processing means,
- input port means for selecting a test target return signal, said input port means operatively connected to said processing means,
- means for converting said digital target return signal to a analog target return modulating signal, said converting means being operatively connected to said processing means, and,
- means for attenuating operatively connected to said converting means to receive said analog target return modulating signal therefrom, said attenuating means receiving an RF signal, said attenuating means in response to said analog target return modulating signal modulates said RF signal to provide a modulated test target return signal.
2. A microprocessor-controlled RF modulator apparatus as described in claim 1 wherein memory means comprises a 20K EPROM memory unit.
3. A microprocessor-controlled RF modulator apparatus as described in claim 1 wherein said converting means comprises an output latch means operatively connected to said processing means, said output latch means buffering data into and out of said processing means,
- a digital to analog converter means operatively connected to said output latch means to receive data therefrom, said digital to analog converter means converting said data to an analog signal, and,
- an amplitude control means operatively connected to said digital to analog converter means to receive said analog signal therefrom, said amplitude control means generating control voltage which is applied to said attenuating means to control the output signal therefrom.
4. A microprocessor-controlled RF modulator apparatus as described in claim 1 wherein said attenuating means comprises a PIN diode attenuator.
5. A microprocessor-controlled RF modulator apparatus as described in claim 1 further including an RF target generator to provide an RF signal to said microprocessor-controlled RF modulator apparatus, said test target return signal from said attenuating means being applied to an RF target horn, said RF target horn radiating said test target return signal to a fire control radar which is under test.
6. A microprocessor-controlled RF modulator apparatus as described in claim 2 wherein said 20K EPROM memory unit comprises ten 2K EPROMS with their respective input lines connected in parallel and their respective output lines connected in parallel, both of which lines are respectively connected to said processing means.
7. A microprocessor-controlled RF modulator apparatus as described in claim 6 wherein said converting means comprises an output latch means operatively connected to said processing means, said ouput latch means buffering data into and out of said processing means,
- a digital to analog converter means operatively connected to said output latch means to receive data therefrom, said digital to analog converter means converting said data to an analog signal,
- an amplitude control means operatively connected to said digital to analog converter means to receive said analog signal therefrom, said amplitude control means generating control voltage which is applied to said attenuating means to control the output signal therefrom, and,
- said attenuating means comprises a PIN diode attenuator.
| 3571479 | March 1971 | Horattas |
| 3718988 | March 1973 | Ball et al. |
| 3783172 | January 1974 | Bernstein |
| 3792475 | February 1974 | Smetana |
| 4168502 | September 18, 1979 | Susie |
| 4224583 | September 23, 1980 | Larkin |
| 4327417 | April 27, 1982 | Zaczek |
| 4334866 | June 15, 1982 | Burrows |
| 4450447 | May 22, 1984 | Zebker et al. |
| 4493647 | January 15, 1985 | Cowdrey |
Type: Grant
Filed: Nov 1, 1985
Date of Patent: Jun 7, 1988
Assignee: The United States of America as represented by the Secretary of the Air Force (Washington, DC)
Inventors: Francis X. Filardo (Shalimar, FL), Michael C. Scott (Panama City, FL)
Primary Examiner: Stephen C. Buczinski
Assistant Examiner: Linda J. Wallace
Attorneys: William Stephanishen, Donald J. Singer
Application Number: 6/793,811
