Passive Electronically Scanned Array (PESA) and the Active Electronically Scanned Array (AESA) are basically same in technology and principles of operation , both systems are capable of steer its beam Electronically through utilization of Phase Shifter hence it could be made in fully solid state configuration where no moving parts required (like APG-77 Radar on F-22 or Zhuk-AE Radar onboard MiG-35) they're only differs in source of Radio Frequency (RF) source The AESA uses multiple numbers of Radiating Elements where each of them have their own Transmitter and Receiver Module, making the Antenna where those modules located become "active" because it can Radiate by itself While the PESA system uses common RF source that usually found in conventional Radar like Klystrons, Magnetrons and Travelling Wave Tubes (this one especially, most common in Airborne Application like Fighter Radar). In Terms of Advantages the AESA system is typically better than PESA because of following factors : 1.because the Antenna Elements contain its own Transmitter and Receiver modules and located Right behind the Radiator, it would have lower or even No accidental loss , unlike her PESA sister which still require a connection to be made between its RF source to Radiating elements , incidental loss may occur. 2. High fault tolerance, failure of some modules will not hamper the operation of Radar (typical AESA Radar may contain 100++ Elements) however the entire device would fail if the failure occurs in 10% of total module counts.
3.No Single Point Failure , since basically each modules in active Version contains its own transmitter and Receiver modules, the passive device however since it still use single Transmitter device like Traveling Wave tube , failure of the transmitter may hamper the RADAR operations
Answers by :Xenostrike 06 a.k.a Stealthflanker an Illegally Banned member from Electrosphere
EDIT- Bit improvements and adding single point failure in previous answer
Just to help point the above answer at the questions Passive systems have a single point of failure in its transmit devices (Travelling Wave Tubes,Wave Guides, Microstrips and Power Dividers as well as Antenna Feed System) . Active antenna do not have a single point of failure and a meant to degrades performance gracefully except probably malfunctions in its tapering systems or when the beam is steered in very high deflection angle which will reduce antenna effective Area, increase beamwidth hence reducing gain an compromise detection range. Active versions are much more flexible as phase can be varied in each or a groups of Radiating elements to create different waveforms or beamshapes .
Passive Load is Load comprising of Passive Components Active Load is the Load comprising of Active Components In Test Boards its better to use Active Loads, If you are concerned about Temperature Variations during characterisation
A Passive Hub is just a connector. It connects the wires coming from different hubs. An active hub acts as a multiport repeater. Passive hub will not regenerate the signal but active hub will regenerate the signal ....... so active hub is better.
Active 3D glasses are far better than passive glasses when used with an active 3D television. Similarly, passive 3D glasses work well with passive televisions. Active glasses have been criticized for their weight in the past. Later glasses are lighter than many passive glasses, have a battery life of over one hundred hours and are proving to be exceptionally reliable.
was grabbed is the passive verb.The passive is: be verb + past participleThe sentence above is a past simple passive sentence. The corresponding active sentence isThe little girl, who was better, grabbed the ball
Active voice is much better than passive voice in writing.
NWB stands for non-weight bearing. Also active ROM is better than passive ROM because your patient is involved in their more in their care and also they are working their muscles more.
Active immunity is generated by your body. So you get active immunity as a result of infections or due to vaccines. Passive immunity is not generated by your body. Here the antibodies are to be supplied. Child gets the antibodies from mother. Alternately you get the antibodies via injections. The effect of active immunity is long lasting. The effect of passive immunity is short lived. So the active immunity is considered as better. The passive immunity has one advantage. It is available with immediate effect, while it takes about two to three weeks, before the effects of active immunity is available.
Active mic usually has battery in it and gives way better sound recording quality than passive one. This is smart microphone if you will and I'd recomment to stick with active if you're doing audio recording or movie at home.
Most are active immunity. These do a better job and the person actually becomes immune. Passive immunity is like 'borrowed' immunity. It lasts only for a short time. You can get by for awhile but can still get the disease.
Most metal musicians like, say Metallica use an active pickup. eg.( the EMG 81/85 )
The following lines may show the difference between active and passive voice.When the verb takes the action from the subject (the doer) and passes it to the object (the receiver), the verb is said to be in Active voice.I helped my friend.When the subject receives the action, the subject is the receiver of the action, the verb is said to be in Passive Voice.My friend was helped (by me).It is better to use active voice if the Doer of the action is known or mentioned. Passive Voice should only be used when it is necessary.Active Voice is better because it is direct, simple, clear and easily understandable without doing any mental exercise.
When the verb takes the action from the subject (the doer) and passes on to the object (the receiver), the verb is said to be in Active voice.I helped my friend.When the subject receives the action, the subject is the receiver of the action, the verb is said to be in Passive Voice.My friend was helped (by me).It better to use active voice if the Doer of the action is known or mentioned. Passive Voice should only be used when it is necessary.Active Voice is better because it is direct, simple, clear and easily understandable without doing any mental exercise.
Active voice: I took the cake. or: I made a mistake.Passive voice: The cake was taken. or: A mistake was made.When the verb takes the action from the subject (the doer) and passes on to the object (the receiver), the verb is said to be in Active voice.I helped my friend.When the subject receives the action, the subject is the receiver of the action, the verb is said to be in Passive Voice.My friend was helped (by me).It better to use active voice if the Doer of the action is known or mentioned.
In a active heatsink system you have both a heatsink and a fan thus for the most part an active heatsink cools better with one exception. Should the fan fail the active heatsink will quickly overheat. Passive heatsinks relay on transferring heat without the aid of a fan. The advantage here is that a passive heatsink is fail proof and uses 0 electricity, however passive heatsinks don't typical cool as well. Passive heatsinks work great for supporting chips and RAM cooling. They are also found in servers because of the no fail aspect. EnzoTech produces some passive heatsinks you can read a bit more about them here: http://electricalninja.com/
Passive Hubs These hubs are nothing more than point contacts for the wires that make up the physical network. An example of this would be a punchdown block that is a simple plastic, unpowered box used to plug network cables into it. Active Hubs Active hubs are a little smarter than the passive hubs we saw. All You might also come across the term "concentrators" which are basically active hubs, concentrating and strengthening a signal as it enters and exits the hub.
3D TVs are a hot issue these days. Some say active 3D TV is better, some say passive 3D TV is better. I didn't see difference when I went to Best Buy.
Samsung, like the majority of manufacturers only makes active 3D tvs. LG and Toshiba make passive 3D TVs. Although there is debate over the better technology, manufacturers are supporting active 3D more than passive. It has had some teething trouble in its early days but recent developments have made it far more robust and the once heavy glasses are now as light as many of the passive glasses.
Because they aren't better than active 3D television. Both have their advantages. Passive televisions use polarizing glasses to separate the left and right eyes' images. The effect is that the perceived resolution is cut in half to 540 lines, less than the 576 lines of older standard definition images.
Smaller, lighter, longer battery life. Passive infrared instead of active. They also work better.
The correct spelling is bitten. The boy was bitten by the dog. (passive sentence construction) better written as: The dog bit the boy. (active sentence construction)
No, of course not (unless you're trying to use it with an intransitive verb). However, use it sparingly and when you do use it, think if the active voice would be better.
Active Voice:In most English sentences with an action verb, the subject performs the action denoted by the verb. Ex:Mary mailed the letter.Mary(subject) is doing the mailing(verb)Passive Voice:One can change the normal word order of many active sentences (those with a direct object) so that the subject is no longer active, but is, instead, being acted upon by the verb - or passive.Ex:The letter was mailed by Mary.The letter(subject) was being mailed(verb):) Hope this helped.Yes.When the verb takes the action from the subject (the doer) and passes on to the object (the receiver), the verb is said to be in Active voice.I helped my friend.When the subject receives the action, the subject is the receiver of the action, the verb is said to be in Passive Voice.My friend was helped (by me).It better to use active voice if the Doer of the action is known or mentioned.
Battery free glasses for 3D are better if they are being used with passive 3D televisions. LG only have passive 3D television so the battery free glasses work with them. The other premium brands such as Samsung, Sony etc all use active 3D and their glasses are battery powered. The active glasses are far better for use with active televisions because the battery free glasses won't work with them. Previous criticisms of active glasses were weight and battery life. With the weight below one ounce and battery life of over 100 hours, neither of these are issues any more.
Essentially, if the causer of the action in the sentence is not named, passive voice is better used. For example: "That dress has been bought" To keep the exact wording of the sentence, you cannot change into active voice. However, if you rewrote the sentence, "Someone bought that dress" you are adding a pronoun to take the place of the unknown causer of the action.