Search Engine

Near Far

Add Question

147 Threads found on Near Far
As far as I see, both ends have the same (13 mm) diameter. The IR sensor is apparently placed under a removable cap near the LCD display (as shown with the 400 photo). The ability to measure the temperature of small devices is specified by the 1:1 spot:distance ratio. A minimal spot size isn't specified, but it will be surely several mm.
Dear all, I am planning to simulate, and in a single setup, an FSS-Antenna system. I need to study the effect of different field patterns of a source antenna on the performance of an FSS structure. The simulation scenario has the following givens: 1- An antenna, in both the radiative-near-field (Fresnel region) and far-field (Fraunhofer region),
The diode is biased near the break down point. Once the diode avalanches it conducts and will remain in a conducting state or have a long recovery time unless quenched. With the addition of RL there is a voltage drop when current flows which will drop the voltage far enough to terminate the conduction in some diodes. In other diodes, especially InG
There's no principle limitation to operate a buck converter with a duty cycle slightly abobe zero. In so far, I don't understand the meaning of the diagram. There's also no limitation for the switch transistor, except for achieving reasonable efficiency. Voltage feedback is presumed, however. Duty cycles near zero will occur in any standard buck
What about the price? Is an outdoor measurement setup less expensive than a big chamber with a near field measurement? And perhaps the outdoor measurement is more accurate, maybe you can find some numbers....
I was wondering if anyone had any experience in near-field to far-field back transformations. I have a simulated far-field pattern and I'd like to back project the fields onto the aperture of the array. I've gotten NF-FF transformations to work and also NF planar back to the aperture to work but I'm having trouble with back projecting (...)
Without seeing your calculation, I don't want to guess finally about the problem. Although 3λ is near field, the field strength won't be be very different from far field value according to Friis equation, presumed you are using simple antennas (e.g. a dipole) and don't have strong reflections.
hi. I have a basic question in FDTD.I know formula and concepts of Huygens surface and I know formulas of near field to far field transformation (NFTFF) and also I can write matlab codes for this purpose.but I have a simple question. for NFTFF calculations,where I should place Huygens surface?before PML or in edge of PML?because as distance from
Hi every body:-) i am trying to design a simple current sensing interconnect , composed of a driver with current Iwin , lossy transmission line with impedance Z0, near and far- end voltage vwin, vout and receiver with termination resistance Rt nad received current Irec, i have 3 simple equations Iwin=IDsat=(w/2l)*mu*cox* (Vgs -vth)^2 ---> eq (1)
A dipole array is boxed in a rectangular box similar to radiation boundary box in HFSS. It radiates at 915MHz. The wavelength at 915MHz is 32cm. The far field is > 16cm. Can the power radiated be measured, say at 10 cm (in the near field) right outside the rectangular box assuming rectangular box is 10cm wide and long? Would the power radiated m
However, if I run the simulation with an airbox which is just very slightly larger than the antenna size, the simulated values become very close to the measured ones. Makes perfect sense. These low frequency "antenna" tags have negligible far field radiation. They work with inductive coupling in the near field only,
I don't see current waveforms considered in your calculation, in so far I don't expect that it's correct for conventional power supplies with filter capacitor. For reasonable filter capacitor values, a "form factor" Irms/Idc of 1.6 for full wave rectifiers and 2.0 for half wave rectifiers is assumed. PFC power supplies have near to unity power f
In HFSS, my understanding is that power radiated from antenna is calculated at radiation box? So, does the radiation box act as a receive antenna? In real world scenario, what is the method to measure power radiated from an antenna? Isn't it to have a receive antenna in the far field or even the near field? Thanks.
For low frequency RFID, the "antenna" tags are indeed inductors. They work with inductive near field coupling, which is different from normal far field antenna radiation.
How current, near and far fields are related, depends on your geometry, and of course wavelength. Maybe you can give some additional information.
Capacitor vs. Battery Capacitor: * store energy in an electric field. * charge stored in a capacitor is proportional to the potential difference between the two plates * is charged by applying a voltage across the terminals which causes positive and negative charges * inner resistance is near infinite. * far lower energy density (compared t
For what purpose the use of "near-Field Sphere" or "near-Field Line" is needed? As much as I know, HFSS solves all the fields inside the far-field radiation boundary. If that is the case, all near fields are calculated by default. So what for does the "near-Field Sphere" or "near-Field (...)
As far as I know, the RFID antennas work in the near-field region, so you must obtain a good understanding of the behavior of your antenna in the near-field.
I don't understand how the waveform with V near 100 V is related to a buck converter circuit with 20V input supply. Subharmonic oscillation, if occuring, is a matter of the switch mode controller, so you should primarly show the controller circuit for a discussion of the effect. As far as I'm aware of, the oscillation occurs in a controller
Please look into a textbook. The near-field zone of an antenna is defined from the ratio of its aperture size to wavelength. Large antennas (with apertures many times larger than the wavelength) in fact shape their main lobe of radiation pattern quite far on axis. Satellite communication antennas (like Intelsat) form their main beam up to hundred