Download  Print this page

HP 8360 User Handbook Manual Page 261

8360 series synthesized sweepers.
Hide thumbs
   
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508

Advertisement

HP 8360
User's Handbook
Uncoupled mode can also be used for the following:
To increase the available AM depth if you are modulating near the
n
minimum power range of the ALC loop.
To offset the power sweep range.
n
To reduce AM noise by operating at a higher ALC level.
n
AM Rate
The maximum AM rate available is limited by the bandwidth of
the components in the RF path. At rates of about 100 kHz, the
integrator can no longer respond so the ALC loop is eflectiwely
opened. The feedforward path provides the capability to modulate at
much faster rates.
RF components in the ALC loop limit the ALC bandwidth to
250 kHz. High power and Option 006 synthesizers are also limited
to 100 kHz by the components in the RF path. Synthesizers with
frequency doublers (A32) are limited by the 100 kHz bandwidth of
the doubler for carrier frequencies greater than 20 GHz. Note that
due to the feedforward scheme, AM bandwidth is not affected when
amplitude and pulse modulation are simultaneously activated.
Deep AM
Deep AM mode is a means of reducing distortion when the desired
AM depth is very deep (greater than 90%) or when modulating below
an ALC level of -20 dBm. Amplitude modulation is summed with
the reference level signal. The detected signal is compared to the
reference. Therefore, the ALC loop should follow the AM input.
However, the detector's ability to sense low power levels limits the
maximum AM depth. When the modulation signal reduces the
output power level to a level which is below the detector's range
limit, the error signal generated sends the integrator to rail, resulting
in gross AM distortion. This is where deep AM mode should be used.
Deep AM engages a comparator circuit (see Figure M-l) to sense the
power level of the detected signal. When the signal level is out of the
detector's range, the loop integrator switch opens (opening the ALC
loop). The output of the integrator is frozen, applying a constant
drive to the modulator. Since the modulator's most linear range is
at low power levels, the AM envelope distortion is minimal. When
the comparator senses a signal that is within the detector's range, the
integrator switch is closed, re-engaging ALC loop leveling.
Figure M-2 shows the leveled AM characteristics in the different
modes. The maximum leveled output with ALC engaged is shown as
the synthesizer's maximum leveled output specification. (Individual
synthesizers may have more power; watch for an
The minimum level is limited by the detector's range (approximately
-20 dBm.) With deep AM engaged, the minimum level (where the
ALC loop is opened) is set to -13 dBm. This guarantees that the
detector can still sense the signal level with no distortion. With the
Operating and Programming Reference M-15
Amplitude Modulation
message.)

Advertisement

Table of Contents

   Related Manuals for HP HP 8360

This manual is also suitable for:

83620a83622a83624a83623a83630a83640a ... Show all

Comments to this Manuals

Symbols: 0
Latest comments: