Antennas

An antenna has been defined as a mean for radiating or receiving radio waves. In addition to receiving or transmitting energy, the antenna is used to optimize the energy radiation in some directions while suppressing it in others. An antenna may be a piece of conducting wire, an aperture, an assembly of elements (array), a reflector, a lens, etc.

There are different types of antennas:

  • A wire antenna kit. Font: Wikipedia
  • A wire antenna kit. Font: Wikipedia

Wire antennas: They are very common. We can see them on automobiles, buildings, ships, etc… They come in different shapes used for different purposes:

  • Monopole: it is a metal pole and it works well to receive signals in a relatively narrow range. They are used in cell phones or AM/FM radios.
  • Simple dipole: they point in two different directions. They are more effective than a simple monopole.
  • Loop antenna: it is a big dipole. It is good for wide range of frequencies, but it is not very effective for specific frequencies.
  • Bowtie: it is a special type of dipole antenna, very good for frequencies in the UHF band.

  • Yagi antenna. Font: Wikipedia
  • Yagi antenna. Font: Wikipedia

  • Yagi: it is the most common antenna in TV signal receiving. Internally, it is composed by a group of dipole antennas which behave like a single device (that is why we call it Yagi antenna instead of Yagi group or Yagi antennas, in plural), aligned one next to each other along the antenna axis (one receiver plus one reflector at the back and several directors at the front). Each dipole has a different size, being tuned to get a specific frequency. They are designed in such a way that one dipole does not interfere another one, but the full set behaves as a wide band receiving antenna.

Aperture antennas: They can have different configurations: pyramidal horn, conical horn or rectangular waveguide. They are very useful for aircraft or spacecraft applications.

  • Parabolic antenna. Font: Wikipedia
  • Parabolic antenna. Font: Wikipedia

Array antennas: Sometimes the radiation of a single element might not be enough. In this case an aggregate of radiating elements in an electrical and geometrical arrangement (an array) will result in the appropriate radiation characteristics.

Reflector antennas: They are used to communicate over great distances. They transmit and receive signals that travel millions of miles. The parabolic reflector for satellite TV signal is the most common.

Lens antennas: They can be used in most of the same applications as the reflector.

If we want to measure the parameters of an antenna we use:

The frequency range, which means the kind of signals it will pick up: television, phone signals, WiFi, etc. They all use different frequencies. Antennas transmit and receive electromagnetic waves. These waves, which take a particular shape, propagate through the air at the speed of light, and they repeat periodically. The faster the waves oscillate, the shorter the wavelenght. The frequency measures how fast the waves oscillate.

Antennas have different shapes and sizes, as different frequencies are better captured by different sized antennas. The measure units used are the kilohertz (kHz), only used for radio, megahertz (mHz), which is used in cell phones, FM, television and WiFi; and gigahertz (Ghz), which is used for satellite signals.

The Gain, which is closely related to directivity. It is a measure which takes into account the efficiency of the antenna and its directional capabilities. Gain means how good is the signal reception when the antenna is well directed to the emitter. It is measured in decibels (dB).

Gain and frequency range work together. An antenna will usually do a certain amount of gain at some frequencies, and a higher or lower gain at some other frequencies.

Distance is as well an important factor. The amount of power goes down at a bigger distance. There is a limit to the distance, at some point it will be impossible to get any signal.

Typical parameters of antennas are gain, radiation pattern, beamwidth, polarization, and impedance.

Storyline

Jordi and Bill are at a client’s house trying to solve his WiFi coverage problems. Jordi is in the kitchen.

Bill:There is no WiFi connection in the kitchen.

Jordi: I suspect the microwave is interfering. Unplug the microwave oven from the socket.

Client: The WiFi is working now. But I need the microwave anyway in the kitchen.

Jordi: The truth is that the microwave is sabotaging the WiFi network. Most problems with microwaves involve products that use the 2.4 GHz band, which can interfere with 802.11g or single-band 802.11n routers.

Client: Then, what do I do?

Jordi: The solution is to buy a dual-band router that operates simultaneously at 2.4GHz and 5GHz.

Bill: I’d also advice you to take proper security measures to ensure your internet connections are protected from unauthorized access by using a secured password.

Client: Thank you. I appreciate your advice.

Vocabulary

  • Radio wave: ona de ràdio
  • Optimize: optimitzar
  • Suppress: suprimir
  • Aperture: apertura/obertura
  • Assembly of elements: conjunt d’elements
  • Lens: lent
  • Monopole antenna: antena monopol (un sol eix)
  • Simple dipole antenna: antena dipol (de dos eixos)
  • Wide range of frequencies: àmplia gamma de freqüències
  • tuned: sintonitzat
  • Aircraft/spacecraft application: aplicació aeronàutica/aeroespacial
  • Frequency range: gamma de freqüències
  • Speed of light: velocitat de la llum
  • The faster… the shorter: com més ràpida, més curta
  • Wavelenght: longitud d’ona
  • Different sized antennas: antenes de diferent mida
  • Gain: guany
  • Efficiency: eficiència, rendiment
  • Directional capabilities: capacitats direccionals
  • Higher or lower: més alt o més baix
  • Radiation pattern: diagrama de radiació
  • Polarization: polarització
  • Impedance: impedància
  • Coverage problems: problemes de cobertura
  • Suspect: sospitar
  • Microwave: microones
  • Socket: endoll
  • Unauthorized access: accés no autoritzat
  • Secured password: contrassenya segura
  • Advice: consell

Grammar

A subornidate clause (Cat. oració subordinada) is a part of the sentence that has no meaning of its own. Its meaning depends on the main clause (Cat. oració principal).

The comparative and superlative sentences are those which are used to compare two or more things. To make comparisons, we must use an adjective (a word which tells a quality or characteristic of a noun) or an adverb (a word which tells how an action is done). In comparative and superlative sentences, both adjectives and adverbs sometimes take a special form, which is called the comparative form.

On the other hand, the relative clauses are subordinate clauses that we can add to a sentence to speak about the characteristics of a noun. In this sense, they are similar to adjectives. All the relative clauses are introduced by a relative pronoun. This pronoun refers to a noun, called the antecedent, of which we say or explain something. The relative clauses are often used to describe things.

The comparative sentences

The comparative sentences are used to compare two things. There are three types of comparative sentences: comparative sentences of superiority, comparative sentences of equality and comparative sentences of inferiority.

Comparative sentences of superiority

In these sentences, we say that one thing is more than another. To express the comparison, the adjective and the adverb take the comparative form, which depends on the type of adjective or adverb. The following tables show the comparative forms of superiority for adjectives and adverbs:

Adjectives:

Taula: comparative forms of superiority (adjectives)
Type of wordComparative formExamples
One-syllable adjectives-ER big > bigger (Cat. gran > més gran)
Two-syllable adjectives ending in -y -IERhappy > happier (Cat. feliç > més feliç)
Other adjectivesMORE + adjective intelligent > more intelligent (Cat. intel·ligent > més intel·ligent)
Irregular adjectives good > better (Cat. bo > millor)
bad > worse (Cat. dolent > pitjor)

Adverbs:

Taula: comparative forms of superiority (adverbs)
Type of wordComparative formExamples
Adverbs ending in -lyMORE + adverbeasily > more easily (Cat. fàcilment > més fàcilment)
Other adverbs -ERlate > later (Cat. tard > més tard)
Irregular adverbs well > better (Cat. bé > millor)
badly > worse (Cat. malament > pitjor)
far > further (Cat. lluny > més lluny)

In the comparative sentences of superiority, the two elements of the comparison are separated by the conjunction than (Cat. que). Here are some comparative sentences:

  • The English grammar is easier than the French grammar (Cat. La gramàtica anglesa és més fàcil que la gramàtica francesa)
  • But the English pronunciation is usually more difficult than the French pronunciation (Cat. Però la pronunciació anglesa és normalment més difícil que la pronunciació francesa)
  • Running is certainly better than smoking (Cat. Córrer és certament millor que fumar)
  • Nowadays we can send a message much more quickly than before (Cat. Avui en dia podem enviar un missatge molt més ràpidament que abans)
  • Cats usually run faster than dogs, don’t they? (Cat. Els gats normalment córren més de presa que els gossos, no?)

Sometimes it is not necessary to include the two terms of the comparison in the same sentence. For example:

  • Which is better -the red one or the blue one? (Cat. Quin és millor - el vermell o el blau?)
  • I think I’ll take a beefsteak although it’s more expensive (Cat. Em sembla que em prendré el filet encara que sigui més car)
  • If you ask for somebody’s help, you will can do the job more easily (Cat, Si demanes que algú t’ajudi, podràs fer la feina amb més facilitat)

Comparative sentences of equality

The comparative sentences of equality are used to indicate that two things are on equal terms. We express the comparison of equality like this:

  • Affirmative statements: …AS + adjective/adverb + AS…
  • Negative statements: …(NOT) SO + adjective/adverb + AS…

Here are a few examples:

  • The son is as nice as the father (Cat. El fill és tan agradable com el pare)
  • You can do it as easily as a child (Cat. Ho pots fer tan fàcilment com un nen)
  • Working too much is as bad as doing nothin (Cat. Treballar massa és tan dolent com no fer res)
  • The speech was not so good as I expected (Cat. El discurs no va ser tan bo com jo esperava)
  • We didn’t finish so early as you had promised (Cat. No vam acabar tan d’hora com m’havies promès)

Comparative sentences of inferiority

This type of comparative sentence is used to say that one thing is less than another. To separate the two terms of the comparison, we use than, like in the comparatives of superiority. We form the comparative sentences of inferiority like this:

  • …LESS + adjective/adverb + (THAN)…

Examples:

  • This programme is less difficult than I thought (Cat. Aquest programa és menys difícil del que em pensava)
  • With the economical crisis, we are less rich everyday (Cat. Amb la crisi econòmica, cada vegada som menys rics)
  • I think the new CEO is less intelligent than the previous one (Cat. Crec que el nou president és menys intel·ligent que l’anterior)
  • I would invest in a developed country. It’s less risky than investing in developing countries (Cat. Jo invertiria en un pais desenvolupat. És menys arriscat que invertir en països en vies de desenvolupament)

Note: the comparative of inferiority is not very much used; when we need to establish a comparison, we tend to use the comparative of superiority.

The superlative sentences

The superlative sentences are used to compare one thing with all the others. As in the comparative forms of superiority, the adjectives and adverbs take a special form called the superlative form. The following tables show the superlative forms of adjectives and adverbs:

Adjectives:

Taula: superlative forms (adjectives)
Type of wordSuperlative formExamples
One-syllable adjectivesTHE -EST big > the biggest (Cat. gran > el més gran)
Two-syllable adjectives ending in -y THE -IESThappy > the happiest (Cat. feliç > el més feliç)
Other adjectivesTHE MOST + adjective intelligent > the most intelligent (Cat. intel·ligent > el més intel·ligent)
Irregular adjectives good > the best (Cat. bo > el millor)
bad > the worst (Cat. dolent > el pitjor)

Note: one-syllable adjectives with a vowel + a consonant double the consonant when we add the ending -est: big > the biggest, thin > the thinnest, fat > the fattest, mad > the maddest, red > the reddest, etc

Adverbs:

Taula: superlative forms (adverbs)
Type of wordSuperlative formExamples
Adverbs ending in -lyTHE MOST + adverbeasily > most easily (Cat. fàcilment > el més fàcilment)
Other adverbs THE -ESTlate > the latest (Cat. tard > el més tard)
Irregular adverbs well > the best (Cat. bé > el millor)
badly > the worst (Cat. malament > el pitjor)
far > the furthest (Cat. lluny > el més lluny)

Here are some examples of superlative sentences:

  • Microsoft is one of the most important companies in the world (Cat. Apple és una de les empreses més importants del món)
  • And Bill Gates is one of the richest people (Cat. I Bill Gates és una de les persones més riques)
  • Talking to the manager was the worst thing you could do (Cat. Parlar amb el director és el pitjor que podies fer)
  • Do it the best you can (Cat. Fes-ho el millor que puguis)
  • She went the furthest she could go (Cat. Va anar el més lluny que va poder anar)

Summary of the comparative and the superlative sentences

We are going to compare the four boxes in the picture below in terms of size. To speak about the size of an object, we can use the adjectives big and small:

Figura Comparative and superlative forms

Now read these comparative and superlative sentences:

  • Box A is bigger than boxes B, C and D.
  • Box A is the biggest of the four.
  • Box B is smaller than box A, but it’s bigger than boxes C and D.
  • Box C is as big/small as box D
  • Box D is as big/small as box C
  • Boxes C and D are smaller than boxes A and B
  • Boxes C and D are the smallest of the four.

The relative clauses

The relative clauses are used to explain the characteristics of a noun. This noun is called the antecedent and it usually appears immediately before the relative clause. Here are some examples of relative sentences (the relative clause is in italics):

  • I haven’t sent the mail that I’ve written in the morning (Cat. No he enviat el mail que he escrit aquest matí)
  • The restaurant where we met is no longer there (Cat. El restaurant on ens vam conèixer ja no hi és)
  • Where’s the person who was waiting for me? (Cat. On és la persona que m’estava esperant?)
  • A job interview is the moment in which you can explain your skills (Cat. L’entrevista és el moment en el qual pots explicar les teves habilitats)

Now let’s see the elements of a relative sentence. The following sentence will serve as an example: We need a person who speaks English and German.

  • The main clause: We need a person…
  • The relative clause: …who speaks English and German.
  • The relative pronoun: …who…

The relative pronouns

The relative pronouns depend both on the noun it refers to (the antecedent) and on its function in the relative clause. Here is a list of the relative pronouns and their use:

Taula: The relative pronouns
Relative pronounIt is used when…
that the antecedent is a person or a thing and it is the subject or an object of the relative clause
whothe antecedent is a person and it is the subject of the relative clause
whomthe antecedent is a person and it is an object of the relative clause
whichthe antecedent is a thing and it is the subject or an object of the relative clause
whosethe antecedent is a person or a thing and it has the function of a possessive adjective
wherethe antecedent is a thing denoting a place and it is an adverbial of place in the relative sentence
whenthe antecedent is a thing denoting time and it is an adverbial of time in the relative sentence
whythe antecedent is the word reason (Cat. raó) and the relative sentence explains the reason of the main clause

As you can see, all the relative pronouns (except that) are the same as the interrogative pronouns.

You should know the following things about the relative pronouns:

  1. The pronoun that can be used instead of who and which. It is mostly used in the spoken language.
  2. Whom is only used in the formal written language. In speech, we normally say that or who.
  3. Which can have a preposition (in which, for which, about which, etc.).
  4. As whose has the function of a possessive adjective, it must go before a noun.
  5. The antecedent reason is often omitted from the main clause: This is (the reason) why I didn’t go

Omission of the relative pronoun

In speech, we often omit the relative pronouns that, whom (who in informal style) and which, but only when they are the object of the relative clause. For example:

  • This is the book that I bought or This is the book I bought
  • Sarah is the girl whom I called last night or Sarah is the girl I called last night
  • The video which we recorded has been lost or The video we recorded has been lost

However, we cannot omit the relative pronoun in these sentences because it is the subject of the relative clause:

  • That’s the book that became so famous last season
  • Sarah is the girl who called last night
  • Here’s the video which explains how to deal with conflicts at work

Types of relative clauses

We can distinguish two types of relative clauses:

1) Defining relative clauses: these clauses define or identify a noun. For example:

  • The people who live next door are the Simpsons (Cat. La gent que viu a la porta del costat son els Simpson)
  • Paris is a city which lies on the river Seine (Cat. París és una ciutat que està a la vora del riu Sena)
  • That was the summer when we travelled to Austria (Cat. Aquest va ser l’estiu en que van anar a Àustria)

2) Non-defining relative clauses: these clauses do not define or classify, but only add some extra information about the noun. It is mostly used in the written language, always between commas (or in brackets). Here are some examples:

  • Mr Branson, who has no experience, made many mistakes (Cat. Mr Branson, que no té gens d’experiència, va cometre molts errors)
  • They say that sake, which I’ve never tasted, is quite a strong drink (Cat. Diuen que el sake, que jo no he provat mai, és una beguda bastant forta)
  • Toronto, where I was in 1984, has grown a lot (Cat. Toronto, on jo vaig estar l’any 1984, ha crescut molt)

Communication

When looking for a job, it is essential to write a good curriculum vitae (or CV). The CV is called resumé (with the graphical accent) in American English. As part of the job searching procedure, it will also be necessary to write a cover letter, which usually accompanies the CV. Both the CV and the cover letter say a lot of things about the writer, so in order to cause a good impression on your potential employer, it is necessary to be very accurate and follow the conventions of this type of texts.

The final and most important stage in the job search is the interview, where you must show your oral skills and control your body language. The job interviews are often carried out in English, even if you are applying for a job in your own country, because a knowledge of English is one of the most important skills for many jobs.

Writing a curriculum vitae

Curriculum vitae vs. resumé

The term curriculum vitae (or CV) is mostly used in BrE whereas AmE prefers the term resumé (spelt with the graphical accent).

You have probably learned that we must not judge people on first impressions. However, when an employer looks at a curriculm vitae (CV), he does precisely that: to judge a person on the first impression produced by the CV, without even knowing the candidate personally.

This is the reason why you should be very careful when you write a CV. It must convince the employer that you are the appropriate candidate for the job. With hundreds of other CVs waiting for an opportunity, the most important thing is that your own CV attracts the employer’s attention. However, to attract the employer’s attention does not mean to write your CV in a variety of colours and/or spectacular font types. This will only distract the reader from the important information. Instead, you should use a conventional format and organize your information clearly.

There are many different models, but the basic elements of all the CVs are:

  • Contact information: your name and surnames should be prominent (usually centered and in bold type). Add your telephone number, your address and your e-mail address.
  • Work experience: your relevant job experience should be listed chronologically, starting with your most recent job. For each job, you should mention the company and your job position.
  • Skills: this section summarizes your personal skills and relevant achievements for the job. Here you should include your language and computer skills.
  • Education: you must list your degrees, the school where you obtained them and the years you were in that school in reverse chronological order.

You may also include any additional information that you think is important for the job (for example, courses you have attended). Except for the contact information, you must include the title of each section, in bold type or capital letters.

Here is a list of things that should not appear in a CV:

  • Errors: making grammatical and/or spelling mistakes in a CV is the worst thing that can happen to a candidate for a job. The employer will immediately relate the mistakes to the candidate’s carelessness and he/she will be obviously discarded.
  • Salary: do not include your current salary or that which you expect to earn. Salary negotiations usually take place during the interview.
  • Irrelevant information: you should only include the information that is relevant for the job and that can benefit your interests. For example, do not include an average mark in a course if it is not a good one or hobbies that have nothing to do with the job.

If you have little or no work experience, you can list your school and social activities and link them to the job you are applying for.

Writing a cover letter

A CV should always go with a cover letter. A cover letter is a formal letter where you explain why you are the ideal candidate for the job. Cover letters have no special format. They follow standards applied to all the other formal letters.

In a cover letter, you should include the most relevant aspects of your experience and education for the post. To do that, you must select the aspects from the CV that can contribute to raise the company’s interest in your application.

Here are some useful expressions which you can use in a cover letter:

  • I am writing to you in response to your advertisement for the post of… (Cat. Li escric en resposta al seu anunci per a la feina de…)
  • As you can see from my enclosed CV, my experience and qualifications match this position’s requirements (Cat. Com pot veure al currículum que adjunto, la meva experiència i qualificacions es corresponen amb els requisits de la feina).
  • I would like to point out that… (Cat. Voldria indicar que…)
  • I look forward to an opportunity to speak with you in person (Cat. Espero tenir l’oportunitat de parlar amb vosté personalment).

Equivalence between the academic degrees in the Spanish and the British school systems

The Spanish and the British academic degrees belong to different school systems. Therefore, it is not possible to make a literal translation of your degrees. We must find the equivalent degree in the foreign school system.

The following table shows the equivalence between the Spanish and the British academic degrees.

Taula: Academic degrees
Spanish school system Brititsh school system
Educació Primària / Educació General Bàsica (EGB) Primary Education
Educació Secundària Obligatoria (ESO) / Batxillerat Unificat Polivalent (BUP) General Certificate of Secondary Education (GCSE)
Batxillerat / Curs d’Orientació Universitària (COU)General Certificate of Education (GCE)
Cicle Formatiu de Grau Mitjà (CFGM) / Formació Professional de Primer Grau (FPI) Vocational Education and Training (VET)
Cicle Formatiu de Grau Superior (CFGS) / Formació Professional de Segon Grau (FPII) Certificate of Higher Education (HNC)
Diplomatura (3 anys) Bachelor’s Degree (B)
Llicenciatura / Grau University Degree
Enginyeria Tècnica Diploma of Higher Education (DipHE)
Enginyeria Superior Engineer’s Degree / Engineer Diploma (DI)
Postgrau (de 30 a 60 crèdits ECTS) Graduate Certificate (PGCert)
Màster (de 60 a 120 crèdits ECTS) Master’s Degree (M)
Doctorat Doctorate (PhD)

You can use a general term to describe the vocational studies. For example:

  • Business Administration and Finance (Cat. Administració i finances)
  • Secretarial Studies (Cat. Secretariat / Assistència a la direcció)
  • Commerce (Cat. Gestió Comercial / Gestió de vendes)
  • International Commerce (Cat. Comerç Internacional)

Preparing your job interview

If the employer has considered your CV, he/she will call you for the job interview. This is the time when you meet the employer so he/she can find out more things about you. The interview may take place in a face to face meeting or online via Skype or any other videoconference program. In any case, the interviewer will ask you about your experience and qualifications, and you will also need to show your skills for the job.

Here are some tips to help you before going to a job interview.

1. Prepare your answers in advance. Think about the questions they employers frequently ask in a job interview and prepare your answers in advance.

Some frequent questions in job interviews

These are commonly-asked questions in job interviews:

  • What can you say about yourself?
  • Why do you think you are good for this job?
  • What are your weaknesses?
  • Why do you want to work in our company?
  • What salary do you expect to earn?
  • What are your motivations?
  • What makes a good team, according to you?
  • Have you got any questions?

2. Make some research. Before going to the interview, look at the potential employer’s website and check the company’s details. Having the information will help you in the interview.

3. Have a good appearance. First impressions are very important, so make sure that you wear smart clothes and have a nice appearance.

4. Be ready. Try to get to the interview with plenty of time. If you get late, you will be doubly stressed and, besides, it will cause a very bad impression. Make sure that you have everything that you need: notebook, pen and a copy of your CV.

5. Show your good character. Although you will probably feel nervous, try to smile all the time. This will help you feel more relaxed and will give a good impression. Make sure that you look your interviewer directly in the eye, and concentrate on what he/she is saying.

6. Ask questions. Do not tell the interviewer that you do not have any questions. You should prepare some questions in advance and be ready to ask them if they tell you so.

Questions that you may ask in a job interview

Here are some questions that you may safely ask in a job interview:

  • Why do you need to fulfill this position?
  • What are the objectives of this position?
  • How do you expect to meet the objectives?
  • What can I expect from you in terms of development and support?
  • What do you do to create a good atmosphere at work?
  • Are there any plans for expansion?
  • What does the company expect from the employees?

7. Take notes. Taking notes will give the impression that you are paying attention and that you are very interested in what the interviewer is saying.

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